When is it appropriate to be "thankful"?

Some positive circumstances of my life are of my own doing. I put myself through college and grad school, I live in a nice place, have more than enough money and food than I need to merely survive another day, my kids are headed toward a happy healthy and prosperous adulthood etc., But these are things that I have accomplished. I really do not have anybody to thank but myself, and that would be pride, not thankfulness.

Some things are not in my control, but they are the result of other peoples proper choices. For example, my parents. They were great people and I benefited enormously from that, but it was their choice to be good parents. I am, to a certain extent, a product of their design. They are both gone, but if I had said “Mom, Dad, I am thankful for you”, my mom would have said “Don’t thank me. Congratulate me for surviving your childhood!” and my dad would have said “Don’t thank me, just make it look like I did a decent job raising you”.

Then there are things that are not in anybody’s control. I missed an airplane connection once and that airplane crashed. I survived the military without getting killed, or hurt in a life changing fashion.
I am pretty thankful for that.

So where does pride and congratulations stop, and “thankful” begin?