I think that you can't really learn what someone has done for you until you have the opportunity to do that same thing for someone else. I understand that my memory may be faulty, and that what actually happened may not be what still lives in my memory, but here goes.
I remember getting a bicycle for Christmas one year. I most certainly remember that it wasn't there the night before, and I remember that on Christmas morning when I went out to the sun porch, my stack of presents was shorter than my brother's. That is, until I turned and saw (it may have had a bow on it, but that would be pretty cliche, wouldn't it?) a brand new, 10 speed bicycle. Of course, 10 speeds today hardly gets you started, but it was a big step up from the dirt bike with coaster brakes on which I'd extended the seat post so far that it was now permanently bent backward.
But it wasn't there the night before, and I'm pretty sure it didn't come fully assembled. Which means that my dad most certainly stayed up late the night before putting that thing together. I haven't any idea how long it must have taken him, how complicated that bike was, or how disassembled that bike was when he got it. I do know, though, that while I appreciated what I suspected he must have done, I never really knew what his work and sacrifice that night meant until I discovered that I'm willing to do that much and more for my own children.
I think that you can't really learn what someone has done for you until you have the opportunity to do that same thing for someone else.