How Long Ago Should We Go Back Into the Memory?

When we talk about our life achievements, learning experiences, etc. How long ago should we go back into the memory? Yes. If you're picking a specific accomplishment and it's further back than three or four years, it has to be really big,. Like, I don't want to hear that you want to math Olympiad when you're a sophomore in high school. You know, that's just living in glory days that are kind of far back.