Hey, I'm no expert - but I think you'll agree the following pieces of my knowledge are quite impressive
  1. When all you lights go off in one room, go to that box in the cupboard and flick the one switch that is facing the opposite way to the rest
  2. Crossy screws are called Philips head - but you're not sure why or if it's one L or two
  3. You can tell if there is a wooden beam behind a certain point of a wall / ceiling, or indeed if a wall is hollow or brick, with a light knock.
  4. Carpets have something called underlay beneath them
  5. Righty-Tighty, Lefty-Loosey
  6. RSJ stands for reinforced steel joist and is a thingy that goes over a door to stop the wall falling down
  7. Spanners come in different sizes and you need EXACTLY the right size