The Weekend's Television: The Children Who Fought Hitler, BBC4, The Secret Life of the Berlin Wall, BBC2

Some small-print disclaimers first, relating to product description. The Children Who Fought Hitler, to start with, a title that conjures up images of human waves of boy-soldiers, running through the rubble-filled streets of Berlin to see who can get to the bunker first and take out Adolf with a Sten gun.

In reality, intriguing though it was, Testimony Films' programme about three alumni of the British Memorial School in Ypres, could more accurately have been called "A Teenager Who Fought the Germans as Well as Two Adults Who Were Children When the War Began", which doesn't have quite the same ring to it. Follow the logic of Testimony's approach and you might equally make a film called "The Toddler Who Shot JFK". And then there's The Secret Life of the Berlin Wall, a title that leads you to expect a film revealing that the reverse side of that forbidding barrier was used as a projection screen for state-sponsored porno films or something similar. In fact, the "secrets" that Kevin Sim's film revealed were that it was awfully grim on the other side and half the East German population were spying on the other half – grave subjects and worthy of airtime, but not exactly classified information for the last 20 years.

Never mind, the title isn't everything, and it's entirely possible for a documentary to fail to deliver the advertised goods and still be worth watching. This was straightforwardly true of The Children Who Fought Hitler, which shone a light into an intriguing cranny of Second World War history. It told the story of the British Memorial School in Ypres, a little corner of a foreign field that was, for a time at least, England. Set up to cater for the children of the British veterans who built and administered the war graves of Flanders, the school imported British values and a British school curriculum across the channel. It was, you might say, founded on the headstones of the Glorious Dead, and, whatever Wilfred Owen said about dulce et decorum, it seemed to have successfully inculcated a very old-fashioned notion of patriotism and sacrifice into its students. One of the former pupils here, a one-time school captain called Jerry Eaton, had left Belgium before the war broke out, eventually winning his wings as a Mustang pilot for the RAF. The two others, a little younger, were among the refugees who set out for the French coast when the Germans invaded. Elaine Madden, a 17-year-old girl, made it across the Channel disguised as a squaddie by a sympathetic British soldier. Stephen Grady, 14 years old and bicycling just ahead of the Germans, was eventually turned back.

It was Grady who really justified the title, recalling the uncomplicated glee with which he and a teenage friend picked up discarded British weapons and grenades on their way back home, hiding them in a field for later use. At just 16, Grady became a section head for the local Resistance, licensed to vandalise on behalf of the Allies and protected by youthful innocence from the full scope of his danger. "I thought if you had a Luger and six rounds you could take on the German army," he said. Putting some of those rounds into an off-duty German officer seemed to have crimped his enthusiasm a little – "I didn't think it was cricket, if you know what I mean" – but even so he recalled the war with almost unalloyed affection as did Elaine Madden, trained up as an SOE agent and parachuted back into Belgium: "These were some of the happiest days of my life," she said of the thrill of liberation. "It was a fabulous feeling."

Memories were far more mixed in The Secret Life of the Berlin Wall, with regret travelling in contradictory directions. There were contributors who were having to live with the fact that they had betrayed their friends, and some who bitterly resented wasted years in prison. But there were also, notably, former socialists who still mourned the death of the society they'd committed themselves to. Kevin Sim's film was a sometimes tryingly affected affair, with the sequence in which a mime artist wordlessly acted out the plight of living under totalitarianism virtually impossible to watch without inappropriate giggles. But there was fascinating material here, too, in particular the interplay of Western and East German propaganda and the astounding scale of the police state. Per head of population, the Stasi was 12 times the size of the Gestapo and 35 times the size of the KGB, and that was without counting the informers. Alfred, one of the true believers, had returned to Berlin from England, hoping to "create a new mental attitude" in the defeated German people. He still couldn't see the folly of attempting to do it with Nuremberg rallies that changed the colour of the flags to red and substituted a more genial kind of lie for the anti-Semitism.