Did you quit for years? What did you lose ability on?

I'm not so sure drumming is 'a thing'...to me it seems to be more of a constellation of 'things'.

With that thought, 'quitting' becomes an odd question of 'what exactly did you quit?'.

Not sitting at a set for an extended period but doing some dedicated pad work? Continuing to sit at your set but not working your composition? Completely walking away and applying no thought/expression work/reading/listening(of any form)?

I find the techniques alot like riding a bike...they come back quickly(well, 18 months or so to get them progressing forward again?)...its the thoughts that have to keep moving or they become far less usable.(can i think about the money beat in several different ways that flavor my 'sitting at the set' or did I walk away from that?0
I walked away completely, and had I known how much work it would take to get back most of it it's questionable if I would've attempted it.
I came back to performing live music to finally play bass properly. That hasn't gone very far.
My elder brother was a competent guitar player and he played professionally and taught students. He inspired me to pick up drums at an early age. Self taught.

First drum a tin can. Second drum a toy drum. Third drum cheap stuff but I upgraded the ride and snare towards the end. Played a few gigs at the age 18. Stopped.

Fast forward to today. Feel for the groove - I kept some.
Right hand much slower. Left hand - totally frozen.
Doubles on the Bass drum - gone.
Chops if I had any - gone.
So, here we are starting from the beginning. Need to go now. It is almost rudiment time.
Started in 1978, I think.
From 1991-2002 I lived in and around NYC for a job and started a family. Since it's impossible to have a drum kit when you live in a small apartment above your landords, about every 9 months I'd get together with friends and coworkers at a rehearsal space in midtown to play for a few hours. But otherwise, I barely played for over a decade.
2002-2006 had a house with a basement and played a bit, if nowhere near as much as I had when I was younger. Got together a few times with guys from the neighborhood..
2007-2017 didn't even touch a drum...other than playing Rock Band with the kids once or twice.
2017 got back into drums for the first time, really, in over 25 years and I had lost speed and stamina. My drumming also had. (Buh-dum-bump.)
I was shocked at how slow my top speed was. My right foot was pathetic. Most of all I was shocked by the fact that my hands in particular but all four limbs in general were just exhausted by the end of a few simple rock songs--I'm talking stuff like "Take It Easy" which should tire out no one. But at first, after just three or four of those kinds of songs my hands were basically incapable of even holding the sticks any longer. It was bizarre. I don't remember being that weak back when I was first taking lessons as a fifth grader. (I probably wasn't.)
Without a doubt - left hand finesse (I'm a righty) and overall resilience (I get pooped a lot quicker). I started playing traditional grip but switched to matched when I returned to drumming after 20+ years away (matched made it easier to reach all the drums/cymbals). Maybe that had something to do with it - however, no intention to go back to traditional.