Knees!
In the last three weeks I've put down battens, new/old oak floorboards and new skirting boards, waxing the lot, buffing (oooohhh eerrrh Mrs!) and polishing.
I no longer have knees - just lumps of indeterminate stuff - bits of bone, sinew, blood, gristle, gravel and sawdust - where my knees used to be!
I'll be fine for an early start on Saturday though.
UTV!