We tend to be too young to fully appreciate our parents, and especially our grandparents. By the time we're mature enough to do so, they're gone or nearly so.
I have gained a huge appreciation for my own parents, now that I'm a parent myself. There's something about staying up late, holding a crying and helpless baby that makes me appreciate all my parents did for me when I was that crying and helpless baby. As a dad I begin to realize that my own dad, someone I wasn't particularly close to as a teenager, once did the things I'm doing now, felt the same love for his children that I feel for mine.
Dad, thank you for all you did. You weren't perfect, but then no one is, and at this point in my life I believe it's long past time for blaming anyone but myself for any issues I have. And, as K (my sister) says, the best we can hope for as parents is that we don't fuck it up in the same ways that they did.... Actually, K wouldn't ever say "fuck it up" but that's the gist of her point, with emphasis added by me. Yeah, we're going to mess up as we raise our own kids, but guess what?, they'll survive and maybe even come to appreciate us, once they become parents themselves.
Thanks again, Dad.