Dutchmen Sport;
Glad your knee replacement worked out but you offer some faulty advice...
Had my knee replacement 5 years ago, worked my butt off in rehab but it just got worse every day. Pain off the chart that no amount of meds could mitigate, swollen, warm to the touch. I spent 17 days in the hospital trying to get enough improvement to just go home and continue PT.
After 6 months I fired my surgeon {the overly pompous head of the orthopedic department... I won't say where} and sought a second opinion. The new surgeon took one look and said: "That's got to come out, you either have an infection or you are seriously allergic to the knee they had put in.
There went 6 months in hell down the toilet. Turns out I am deathly allergic to Cobalt, a significant ingredient in my Cobalt Chromium knee. Two months later they cut my leg off for the second time, a "revision" which is doctor speak for we didn't get it right the first time... this trip back to surgery bought me 14 days in the hospital.
The ceramic knee they used the second time works but the two surgeries left me with so much scar tissue it will never be fully functional. The point being before you let them put in a knee {or hip for that matter}, find out what they are putting in and make sure you are not allergic to it. Reactions like mine are rare but trust me, you do not want to be that guy.
My original surgeon kept telling me to "just keep doing your PT" insinuating I was the problem and not working hard enough. That jerk cost me a couple of years that frankly, I don't have to spare. Sometimes the problem isn't that the patient is not working hard enough and yes you can easily overdue your post-surgical physical therapy.
Following TKR you will have lots of serious pain and need to put in the time doing your physical therapy but overdoing it is not a good way to go. There might just be a very good reason you are not making the progress someone else thinks you should.
:S