You seem to have multiple degenerative issues in the knee. Degenerative tears at age 73 are quite common and the issue is rather than they lead gradually to osteoarthritis of the knee, rather than being a crippling problem in their own right. It may be the partial tear of the meniscus root that caused the pain.
Peripheral tears in younger people often heal, but really after only 4 days your 'resolution' is not due to 'healing', but may be rather that the resting of the knee has settled any inflammation related to the root tear, or maybe the Baker's cyst has settled because some swelling has gone down.
I imagine that most surgeons would suggest that you keep off sport, keep the leg elevated when at rest, just do gentle exercise with support, perhaps use a compression bandage - and give it a couple of weeks to see how things go.