He doesn't need to have had a childhood dream, though. If he wants to continue playing in the Premier League, which is entirely feasible and frankly quite likely, and he has his mind made up that he's leaving Arsenal, which is seems he has, then all he has to do is make it clear to Wenger that he will only sign for Club X, Y or Z in England.
Wenger is then faced with the option of sell him now or be stubborn and lose him for free. I'm quite sure he's pragmatic enough to realise that selling him now is the only real option.
There's one person who is in a position of power in this transfer, and that's the player.