So - for the first time in the Monkey's life, we've actually washed him down with a soap-based product (normally a washcloth and enough warm water produce the desired results). You can probably guess the reason.
I suppose it was my fault. I'd given the Monkey some banana to nosh on after his lunch, and at some point he got a tiny little piece stuck on his 'free' hand. At one point he wiped this hand in his hair, and I said - stupidly, in retrospect - "Are you wiping banana in your hair?". Well, he took that as a cue to apply the half-banana segment in his other hand to his head - as if it were an eraser, and his hair was a stubborn pencil-drawn thatch. My reaction was somewhere between horror and amusement. Yeah, I know, novice mother - because it was all that he was hoping for and more. After that, every time he managed to catch my eye, the banana-head-rubbing was repeated with a huge grin. Eventually I confiscated the fruit, as it became clear that it wasn't going to morph back into an edible product as far as he was concerned - and to be honest, as far as I was concerned either.
Banana is damn sticky, that's all I can say!