I realize that I've changed. I'm different now than I was 10 years ago, 5 years ago, even 1 year ago. Some of the change is represented by tangible things. Things I can measure and say, "Well 10 years ago, I would have done X, but now I do Y." These have to do with the way I spend money, the way I spend time, the things I yearn for, the way I prioritize my social life. Stuff like that.
But there are other ways I've changed that I can't quite put my finger on. There's a deep pit in my belly that tells me, "things are different now" and "I'm different now."
And then every once in a while, the pit deep in my belly will say to me, "I think you're in the middle of changing RIGHT NOW," and I'll feel butterflies down there in the pit and I'll feel sad and nostalgic for a bit. And then I'll feel excited, because whenever things change, after the sadness, there is newness.