Ive lack cartilage in my knee and for almost the last 4 yrs ive been taking glucosamine and lately my knee feels better, is that why? ive noticed that

Could be: glucosamine seems to help some people with osteoarthritis. It may be helping you. And it's also true that there are many factors that can affect pain and dysfunction in OA: body weight, muscle strength, climate, emotional states, cardiovascular conditioning. Best results if you can have healthy weight, reduce stress, keep your leg muscles strong, and be happy! :-)