It seems that each person's story of TKR is different. The human body is not like an automobile where you replace a component like a water pump and drive it off.
Make sure you get a orthopedic surgeon who specializes in knees and does scores every year. Mine operated a couple days a week doing at least four a day.
I had my right knee replaced in October of 2012. I was off all opioids in three days by using THC candy which is legal in Colorado. I used it only at night for sleeping for about 10 days. During the day I used Tylenol and ice. Get off the opioids as soon as possible. They make you stupid and constipated.
I was walking unaided in a few days. The key is physical therapy. You want a PT who pushes you not hold your hand. I made PT my full time "job". I was on a stationary bike in a little over a week working my knee a couple times of day and doing my exercises two or three times a day. Every few days I would take a rest day. Most people who have issues don't do the exercises as prescribed because they are afraid of pain. You're not going to get better without some pain.
I was dismissed by the doctor and rehab in seven weeks and hiking the Superstition Mountains in Arizona in ten weeks. I'm no elite athlete although I'm fit for my age and not overweight. My wife just says I'm a tough old bird.
My replaced knee quickly became my stronger one. After favoring it for several years I had to learn how to walk correctly again. I just had the other knee scoped and the doctor said I'll have to have it replaced in a couple of years. I'll not think twice about getting it done.