The teenage boys are just as boisterous on the train now as they were half an hour ago performing outrageous gymnastics on the beach, which in itself is pretty impressive, particularly if they’re practicing Ramadan and leaping around like that when they can’t even take on water. Now, on the train, they jump off and run from carriage to carriage at each station, open the doors while the train is moving, swap shirts and throw bags at each other: we just smile at the fact that wherever you are, whatever the culture…..boys will be boys. We are on the short suburban railway which runs out from Tunis, across the water…