Missed that one...

this is why I hate its vs it's. if "it" was Dave, it would be to Dave's full advantage.

this shit will likely never make sense to me.

As noted grammarian Dave Barry notably said, the purpose of an apostrophe is to alert the reader: "look out, an 's' is coming!"

English speakers use has/have/had to signify perfect tenses, meaning the actions are completed but have effects that continue.

So past perfect: It had helped me. Present perfect: it has helped me.