Well Mr. Smartypants, I'll tell you.
You see, when I was but a wee lad of 13, I took my Suzuki RM125 out for a ride at the nearby "track" that was out in the boonies about a mile from my house. Being an asshole kid, I rode it on the streets to get there. At a blind intersection between the dirt road I was on, and a paved road with no stop or yield signs (uncontrolled intersection), I had just crossed onto the pavement when I was hit by a lifted Chevy 4x4 Stepside truck that the cops estimated was traveling at approximately 75 MPH. I was only doing 15-20. After crushing my left leg, I went through the windshield head/hands first before being flipped onto the roof of the truck and eventually onto the ground.
Among my 47 bone fractures, were ALL of my fingers on BOTH hands. Some in multiple places. My right middle finger was nearly detached.
It hurt.
My hands (along with several other joints) never fully recovered. I ended up getting severe arthritis in my hands that requires getting steroid injections every 3 months, if I don't get them, my thumbs in particular are useless.
So, as a result, I have general weakness in both hands, and a good deal of dexterity loss that makes playing guitar at all, a major challenge. I use 9s on most of my guitars, because I quite literally can't manage any higher gauges at standard tuning. For my Eb tuned guitars, I use 10s.
I hope that answers your question well enough. If you'd like to discuss some if my other horrific injuries that came with lifelong consequences, by all means, don't be afraid to ask.
I also love having to explain how I manage to talk/sing after smashing my face through a steering wheel when I was 16, and ripped my 5 front upper teeth out while still attached to the bone, effectively bisecting my upper pallete and having to undergo several major reconstructive surgeries just to be able to have a partial bridge of fake teeth.
Good times.