I keep a full screwdriver kit (26 piece kit) at all times, up to date. I also double up on very used stuff like #1 and #2 Phillips as they are what I most commonly use. As well as my dad has a full set of screwdrivers as well.
About loosing things, I was having a fondue and had it all ready except for the fondue fuel. I searched and searched and searched, couldn't find it tried kerosene. Burned black, created suit and wasn't able to cook the food. 10 min after i finally cooked the food (on the stove), I found fondue fuel.