My 5 year old son (name removed to protect the innocent) was helping me replace a door in one of the bedrooms in our home at the weekend (yes, I spent half the week hanging doors, and then half the weekend too!). Our conversation went something like this:

Me: Does it look like the door's a good fit now?

Mini-me: There's quite a big gap at the bottom daddy.

Me: That's OK - that's to make sure the door doesn't scrape on the new flooring.

Mini-me: I suppose if the gap at the bottom is too big, we could always cut a bit of wood off the top of the door and stick it on the bottom....