Why Won't People Accept Your Help?

Why is it, when you try to help people, they ignore your help. I talked to a lady at the store and she told me she had arthritis in her hip and her ankle. Being that I just had my ankes and my hips replaced 4 years ago, I asked her if she had any cartiledge left. She said yes. I told her I had none left, that it was bone on bone in my situation and that's why I had to get both my hips and ankles replaced. I told her as long as she had cartiledge left, she could do something about it. I told her about a natural drink that I've been using for the last 2 years that absolutely changed my life. I no longer walk with a cane, or a walker because of this juice. i know it was the juice and not the surgery, because 7 months after my first surgery, I was still walking with a cane. She just told me flat out no. There was no proof, and she had no interest. Have any of you had that experience?