Not to be that guy but no one expects someone to stumble on earlier posts and thus not repost them. But you can quite easily search for them before reposting the exact same thing. One requires luck the other requires care. It's similar to not asking for support with an issue that's already been discussed in a separate users question.
Statistically sure but then it's on the algorithm to recommend stuff that interests you more. Reposting things is just spoofing the recommendation algorithm and making things more likely to bubble up to you which is always going to cut both ways. Some people want duplication, others don't.