I've had a tough time with my knee replacement from 6 months ago. It still gets painful/swollen if i get too rough around the farm. Still wakes me up several times a night hurting. I've had some tell me it takes a year for some folks to get over that. I am retired at 67 (almost 68). Mine was in bad shape before the fix. Everyone is different and ymmv. I did all the therapy and went through the exercises. Just taking longer than I figured. Doesn't slow me down just wears me out from the day. I changed the transmission fluid/filter on my 2018 Frontier today and it's not really bothering me right now. Mostly if I am on my feet/knees most of the day. I had a lot of trouble climbing a ladder at the 2 month mark.