Past perfect with "for the last/past..."

1) A couple of minutes ago, I was finally able to finish the thing I'd been working on for the last 10 years.

2) You meet a friend for the first time in a long time and he tells you he's married.
Wow. I had no idea you'd been married for the last five years!

3) A couple of minutes ago I noticed he had been standing there for the past 2 hours. (he's still standing)

Which tense am I supposed to use here? I used the past perfect because of the tense agreement rules, but these time clauses confuse me and make me want to use the present perfect (last,past)

It's really confusing because then why does something like this work:
"Huh. That's weird. I thought I did that yesterday".

Thank you..