I know this has probably already been asked, but I was under the impression that when I liked a post, I gave the poster my own reputation? It sounds really dumb I know, but like for example, say I have 10 reputation and I like a post from somebody with 0 reputation. That person's reputation increases to 1, and mine goes down to 9. Once again, it doesn't make much sense when I think about it, but I've been afraid to rep people for the past year or so because I thought that was the case.