I was always too poor to ever expect anything but a cake for my B-day. Both parents dead by the time it was 25. What I wouldn't give to have them back to see my son who is 30 now. I'd love to tell them thank you for all of the sacrifices they made for me and sis.
Are you being petty? Yeah, somewhat. It's a fact that parents have "favorites" and grandparents do too. Big deal. Sounds like you had a pretty good life growing up.
Be glad you are healthy, have a great wife, and living parents. Life's too short to worry about who got what.
Chill my fellow Texan