Piggybacking Ideas – Ok?

I’m not sure what the internet etiquette is for piggybacking on ideas. Sometimes I feel like I’ve lived two lives, and when I read someone’s post it triggers that memory and then I want to share it. But I don’t want to seem like I’m always just saying, “oh yah I’ve done that too”. Even though that is basically what I’m doing. I think the root of the issue is me forgetting that I have all sorts of things to share from the insanely busy past 15 years of my life. Do you find yourself doing this as well? Is it considered “uncool” to post right away your own story? or am I just being worried for no reason?