How to deal with a friend who dismisses you?

Anonymous

I have a friend who would always dismiss whatever I say when I talk about improvement techniques. Heck, this happens with some other people I know too.

Then later down the line, this same friend/person would suddenly tell me about the same improvement technique or thing I told them about weeks ago.

E. g.
Me: "I read that you gotta train so-and-so to get better at it."
Him: "Oh I am not interested in all these details, sounds troublesome."

*Weeks later*
Him: "I asked this guy and he said you gotta train in this manner to get better."
Me: (That's exactly what I told you weeks ago...)

Then it happens again and again and again...

Updates
28 d
We have known each other for more than 10 years. We hangout together a lot like going to movies, resort, arcade, etc. I even helped him when he was on crutches for a few months.
How to deal with a friend who dismisses you?
6 Opinion