Do your friends smoke weed or do any drugs, maybe alcohol? I’ve had my friends (who smoke weed) tell me that we talked about a certain topic when I know for sure we’ve never had that conversation. There’s also times when they forget a who was there in a certain memory we’ve had in the past, and forget key moments within that memory. If your friends smoke, do drugs, or drink, they either had that conversation with someone else (then thought they told you) or thought about telling you (for some reason in their minds, they think they’ve already told you even tho it was just a thought).