Well, we've just handed my 18 month old nephew, Albert back to his parents after looking after him for, ooh... a day and a half.
And we're knackered. He was, of course, utterly wonderful (though the time when he flung himself into my arms from halfway up the stairs was a moment I could have done without) but very, very tiring. How do the parents among you do it?
I'm not a parent myself, but I can sympathise with the "kid that flings itself into your arms from way-too-high" feeling". I had the niece of my best friend do that to me, and while it only lasted a second and I did catch her exactly as she intended I think my face turned completely white for an hour or two as I was way too far for her to be certain I'd catch her.
Ahh, kids... I sure love'em and have lots of fun when they're around (especially my own nephews) but after visiting a few countries in which the average age for fatherhood is 25 (ie my age) I'm glad that around here I won't start feeling the pressure to have some until my early thirties