It's a joke on what's apparently a common theme. I've all got a bazillion 10mm...except when I need one. I certainly wasn't aware it was a "thing", I thought it was just me. It's probably the most common metric size, it's on everything, my tools end up spread all over various garages and outbuildings. With the inevitable result that when I reach into a tool box, the 10mm are all gone. Working on something, come to a 10mm fastener, it's "aw ****"...because now the hunt is on. Again. Or if there is a 10mm in the box, it's exactly the correct configuration to guarantee busting my knuckles. Which leads to buying more 10mm in various configurations, because hey, I'm getting too old for this ****. Which leads to "How many different variations of 10mm do you own?".
When I was a young lad, my tools fit in one box I could actually carry, my floor jack cost me $14.99 new (still got it, still use it, been rebuilt a half dozen times), my air compressor was a well used Craftsman that cost me $10...and I managed to work on dang near anything. I'm no longer a young lad, I don't work on cars for a living, could really care less if anything I'm working on ever works/runs/drives again, and when I'm not screaming at the neighbor kids to "Get off my lawn!", I can indulge myself in the one thing that actually makes my flinty shriveled heart go pitter pat; tools. All the bright shiny tools, in multiple variations, that the young lad I once was, lying in the mud, with my pieced together set of mis-matched cheap tools, trying to get the job done, once wished I had.
