Great Expectations

Do you ever expect too much out of something, and then later realize it was wonderful. Why is it in the moment we can think that this relationship, job, or whatever the experience may be needs this or that. We think it isn't near perfect and can and sometimes must get better. Time passes and that relationship, job, or whatever the experience is over and we miss it so much and all we can think of is how great it was.
This has happened to me more than once, I must admit. The most recent experience has made me wonder why I feel this way. The questions that I have been asking myself are 1. Do I miss this, okay in this incident it's a relationship, do I miss this relationship because I don't have a relationship similar to it now? Which is a very valid question. I don't have a relationship like it, not even close. But when I start thinking of what this relationship had compared to others, I only think of the good, fun stuff.
2. Was this relationship great, and I took advantage of it? I know that some of this is true. But why is it when I am with this person I love what we have but am fine with the minimal friendship and am never really sure that it needs to be more. Then when I am away from this person, I think "stupid you, look what you are missing?"
So as you can see I have a little conundrum here. Sometimes I think I just miss this amazing friendship with this person, and it was never meant to be anything more, but since I am not dating anyone I wonder if I am missing something. And then maybe I have expectations of what should be and those are just unrealistic.
I am not sure and really only time will tell. I do miss this person and although we are still great friends, I miss him being near. And who knows he may be a lifetime great friend at the least and some people never get that, so I am super lucky, and maybe he is more. But I do know I will be more greatful for the great friend he is now.