He met the Great Hiker in the Sky decades ago and I never met him. I've never even seen a picture of him. The little I know is from my dog-eared guidebook. And yet there he is, prodding me with his stick, goading me up the mountain, urging me on in his Mancunian accent: "Go on lad!"
In 1919, having reached the half-century milestone, good old Eustace took up hill-walking. Just a few months later he'd completed the Welsh Three Thousands in 22 hours 30 minutes, on his first attempt.
Let me put that in perspective. Eustace's troublesome feet had walked, scrambled and climbed for 27 miles over some of the most rugged mountains in the British Isles. He'd conquered Snowdonia's "14 peaks", all 3,000- footers: a total ascent of 13,000ft - half the height of Everest. And in less than 24 hours. What a man.
Hardened walkers and mountain people may now say: "Pah! An afternoon's stroll, a day on the beach." Certainly, since the heady days of Eustace Thomas and the Manchester Rucksack Club the Welsh Three Thousands have been done in staggering times. They've been walked in less than nine hours; run (yes, run) in four hours 20 minutes.
But, as my guidebook says, Eustace was 50 and overweight. He'd only just started hill-walking. I was 35, felt fit as a fiddle and had feet Eustace would have admired. But on my first attempt I failed, miserably.
On peak number five, the weather closed in. I sniffed the air like a true man of the hills and concluded it was to be dangerously horrible for hours. So I walked off the mountain, whereupon the sun came out and shone beautifully for the rest of the day. I was too depressed and tired to climb back up. Instead I found solace in a tea-shop and the largest piece of cake in Snowdonia, resolving to be back.
This year I tried again.
If Eustace did the walk today he'd have to climb 15 peaks, not 14. Ordnance Survey re-measured and found another summit over the magical 3,000ft mark. Oh joy! Nevertheless I was heartened because the extra peak was the last but one - if I got that far I surmised I'd be skipping over it whistling "Climb Every Mountain" ... if I got that far.
So at 5am on a warm May dawn off we set, rucksacks and walking boots, a couple of old friends, plus me and Eustace.
Peak number one is Snowdon herself, Britain's second highest summit. She's called Yr Wyddfa in Welsh - the "tomb". The views from the top, though, make you feel truly alive: sweeping across Cardigan Bay and the northern coastline of Wales, around to the ranges themselves. Here there is space, time and wondrous beauty.
In front of my eyes feathers of mist, dawn-gold, laced the crests and the pinnacles. Precipitous cliffs plunged into bottomless lakes. It's a place of legends.
My trusty guide revealed that King Arthur fought a battle near here and was mortally wounded, but not before he killed his foe with the mighty Excalibar. But no time for that - we had peaks to conquer.
While the next climb was an easy walk, the third developed into a white- knuckle scramble along a knife-edged crest. Snowdonia lay beneath our feet. It was heady, exhilarating, frightening stuff. My friend Gordon suffers from vertigo and had to yell to himself "Come on, Gordon" at the top of his voice to force his way on. Gordon needed Eustace, but Eustace was too busy telling me not to be a wimp.
Three down and feeling good. It was a gorgeous, sunny day and the grass was springy beneath our feet. The descent down to the village of Nant Peris was invigorating: the warm scents of early summer, the soothing hum of the mountain bees, the skylarks warbling high above.
Yes, it was too good to be true.
All the height we had gained on Snowdon had been lost. The first vague feelings of mild despair crept in as ahead peak four cast her shadow across our path like some Arthurian monster, its southern slope scarred with quarries and slag heaps. It is called Elidir Fawr and is so steep the incline seems to be inches from your face as you trudge up. By now it was 9am and steaming hot. Sweat was pouring, legs hurting, the summit just a taunting vision. Eustace gave me a good prod, "Come on lad, keep going, no resting, on, on, on."
You really can't stop. If you do you might as well get the picnic out and check the bus timetable. "The summit, the summit, the summit," urged Eustace. "How, when, where?" I pleaded.
And that's the thing, the mountains play games with you. Their favourite is called: "Now you're there, now you're not". The idea is for the mountains to make you think you've seen the top, when in fact you haven't at all. You get within 10 feet of what you believe is the summit, and suddenly you see there's another 150 to climb. And it happens again and again, often five or six times. I hate false summits.
But there was no time to dwell on it. Onwards and downwards, to lose a mountain of height only to climb another towering, craggy crest. And so it went on. The legs were beginning to reach that trembling stage and we'd hardly started. Every now and then, just to rub it in, super- fit runners would leap past us like Lycra-clad mountain goats, hopping effortlessly from crag to peak, running lazily up slopes that made us wince.
By 2.30pm we'd conquered number six. Conversation, though, was no more than a grunt and a fearful gesture towards the giant, looming Tryfan - number seven.
Tryfan is hugely impressive to look at. A vast, wedge-shaped peak that sticks out from the ridge; buttresses and gullies overlooking the shimmering Lake Ogwen way down below. But at that moment, as an obstacle, it was terrifying.
"It might as well be K2," I said to the others. They were already on their way up.
You know how on Greek islands you see donkeys traipsing wearily up steep, winding paths, snorting for breath under overweight tourists? Well that was us slogging up Tryfan.
We got there, mostly spurred on by the thought of sustenance at a car- park cafe after the next descent. But by now my feet had turned traitor. Eustace did not know what trouble-some meant. It wasn't blisters, just fearsome pain from a pair of boots a size too big, I'm ashamed to say. With every downward step my toes would be scrunched up with 14 stone of weight behind them.
Throbbing and hobbling, I limped along the joyfully flat A5, past the cool waters of Lake Ogwen into the welcome arms of a chair outside the cafe. Unbelievably it was 6pm. We'd been on the go for 13 hours and we'd climbed only eight peaks. There were still seven to go. The three of us sat there and considered the wisdom of continuing. The summit of peak nine, Pen Yr Ole Wen, 3,210ft high, looked down on us and had a good chortle.
We decided to go out fighting. By 8pm we'd hauled ourselves up the ninth, knees creaking and muscles screeching, but the writing was on the wall. Eventually, around 10pm, as the night closed in and the wind got up, we abandoned the mission for fear of losing our way.
Ten peaks done, but failed again! I like to think we were beaten by darkness, although Eustace had long given up the ghost. No doubt he'd deserted for the Lycra-clad mountain goats, a much better bet.
How did he do it all those years ago?
Whatever it was his weak digestion digested, I wanted some. "Eustace, next time, I promise, mate!"
National Express coaches connect to Bangor. From Bangor, there are six buses a day to Llanberis, at the foot of Snowdon. Virgin Trains and North West Trains connect to Bangor.
WHERE TO STAY
The Beddgelert Antiques & Tearooms (tel: 01766 890543) offers b&b in a twin room for pounds 17.50 per person per night, based on two sharing. The Heights Hotel (tel: 01286 871179) in Llanberis offers b&b in an en-suite double for pounds 40 per night, based on two sharing. The Royal Victoria Hotel (tel: 01286 870253) offers b&b in a double room for pounds 46 per person, based on two sharing.
High Trek Snowdonia (tel: 01286 871232) organises guided Welsh 3,000 weekends.
Snowdonia has a Mountaincall weather service (tel: 0839 500449).