You can never have too many tools. This from a guy who has specialty tools that most don't. Like a tool to remove the element from your water heater. Used it twice, well really once once both elements, may never use it again, but ya never know.
Unlike kitchen tools and survival items - never have a one trick pony - I have some tools that are made to do one thing, but do it well - like a basin wrench.
I have 5 or 6 hammers, one rubber mallet, 2 FUBARs, a socket set, screwdrivers galore, levels, speed squares, pencils, saws, wrenches both sae and metric, and much more. Those are just the hand tools. I also have 6 or 8 books on repairing stuff.
If something breaks on a weekend and I can cobble it back together to last til Monday, at least I saved a weekend service charge.
What do I use the most? The internet when I am doing something for the first time.
Guess working in the hardware section at Homeless Depot was good for the garage tool area.