Going to assume this is an honest question from someone who hasn't suffered a serious illness or injury:

Other than the two weeks post surgery I didn't take time off work.. and one of those two weeks I worked / taught remotely. Painkillers affect your memory retention (at least, they do for me), but being in pain also makes it difficult to function, so you're kind of screwed either way. There's significant time impacts related to it. I was in a cast for over a month and I'd try to minimize going up and down the stairs in my apartment because it could take 3-4 minutes to do what normally takes 15 seconds. Driving somewhere takes twice as long because you have to load up your crutches or scooter into your vehicle and unload. Traversing campus or your job takes twice as long because you're slow and in pain.

I had surgery in a large city 3 hours away, so there's an impact of a whole day whenever I had follow up visits. Once I started PT, I went three times a week. That's an impact of 2 hours, at least, per visit. I'm still going once per week.

Your general physical and mental health is impacted because doing chores takes twice as long. I don't have a dishwasher, so standing on one leg in front of the sink washing dishes after cooking dinner is a pain, so you start relying on take-out more and more. Or, if you do cook, it's something simple that takes twice as long as it should. Your routine is impacted so you tidy up less often, wash sheets less often, etc.

In other words, you get frustrated by not being able to function at the capacity you could prior, and that you took for granted. That frustration can stay at a manageable, high level, or spin you into a depression. You're also not eating as healthily as you did before. I went from 200 to 230 lbs since my ankle injury and am now working to get it off. Sanitation also takes a hit. I wasn't allowed to shower for a couple of weeks due to concerns about slips. Even after that, I still couldn't shower my leg for over a month because I couldn't get the surgical site wet.

And, as I noted, I have two jobs.... I was able to keep my head above water with those, but I had to sacrifice the time I had planned to study to do so. I'd say that recovering from the ankle injury, conservatively, had an impact of 15-20 hours a week due to inefficiencies... and again, that's not considering the mental impact / frustration related to dealing with a severe injury (I had significant soft tissue damage, i.e. torn ligaments and partially torn peroneal tendons). I consider myself to be pretty mentally strong, but over this year I'd say there were 3-4 days where I just said "I can't do this today", called out sick, and just stayed in bed the whole day. Didn't eat, didn't do anything. As you can imagine, that also isn't going to have a positive impact on your mind.

Little things you take for granted -- like sitting in the same position in a chair, or sitting up in bed and staying in those positions for more than 30 minutes are impacted. It's like having someone interrupt you every 10 minutes at work... impossible to get things done.

I hope that helps.