Collymore's potential has never been in question; a cruiserweight's build, powerful, quick, two-footed, the very sight of him is enough to make defenders nervous.
In trying to make something of Collymore the sports psychologist concedes that enthusiasm, like courage, comes from the womb not consultation.
One theory is that the only way to get footballers to perform at a proper level of intensity is to bang a drum loudly and constantly. That had no more effect on Collymore than the tea and sympathy he got from Gregory's predecessor Brian Little. If any one factor prompted Little's departure from Villa Park it was Collymore's lethargy.
In a newspaper article on Saturday, doubtless a nice little earner, Collymore raged at critics from his profession. The impression you got was that he had never once asked himself why so little had been achieved with so much ability.
It will take a great deal more than Collymore's outstanding performance against Liverpool to answer the questions about him. So far Collymore has consistently defied the theory that a sure way of getting footballers to perform at or near their peak is to surround him with good players and a good coach and a good organisation that pays him well for his trouble.
Collymore's match-winning performance against the club that was glad to see the back of him last summer merely extends the issue of a consistent attitude.
A thought for Atletico Madrid, who play Villa in the Uefa Cup tomorrow, is that they might have to revise their opinion about Collymore. "He looked very dangerous," said the scout they sent over.
Of course, the circumstances were to Collymore's advantage. Up against the club who dumped him, held accountable for Little's frustration, he tore into a defence made nervous by the sudden change in him.
Liverpool's high standing reflects the Premiership's technical shortcomings; a hesitant defence, no genuine purpose in midfield, no convincing shape.
Roy Evans' weary expression was understandable. To hear him suggest that the referee Graham Poll, who proved to be unusually benevolent, could have sent off three Villa players simply didn't sound like a Liverpool utterance.
One of that trio was Collymore who received only a stern lecture for pulling down Steve McManaman after being booked in the first half.
From Villa's point of view the sight of Collymore getting so involved was a big bonus. Alive at last, he got more involved than any of Villa's supporters could remember.
With Villa a goal down to Michael Owen's penalty after only six minutes Collymore soon responded to the impression that he was unusally committed, equalising with a deflected shot when Liverpool were thrown into panic by a low centre.
Collymore's second was something of a gift, the ball coming to him a few yards out when Ian Taylor's shot rebounded from the foot of an upright. But it was Collymore's overall performance, his willingness to chase lost causes, the powerful surges and constant harrying that excited Villa's supporters. When an ankle niggle caused Collymore's substitition 13 minutes from time Liverpool were again glad to see the back of him but for a different reason.
Here was the player they believed he could be, all they imagined. A snip in Gregory's mind but only if it goes on happening.
Goals: Owen pen (6) 0-1; Collymore (10) 1-1; Collymore (65) 2-1.
Aston Villa (3-4-3): Bosnich; Ehiogu, Southgate, Scimeca; Grayson, Taylor, Hendrie, Wright; Joachim, Collymore (Byfield, 77), Yorke. Substitutes not used: Charles, Nelson, Collins, Oakes (gk).
Liverpool (4-4-2): Friedel; Jones (Murphy, 76), Carragher, Harkness, Bjornebye; McManaman, Ince, Thompson, Leonardsen (Berger, 80); Riedle, Owen. Substitutes not used: Kvarme, Rizzo, James (gk).
Referee: G Poll (Tring).
Bookings: Villa: Bosnich, Collymore, Yorke. Liverpool: Ince, Carragher.
Man of the match: Collymore.
Attendance: 39,372.Reuse content