The biggest change

Strangely enough, there's one question I've gotten lately, from several people (and even from people I never expected it from), and though it really shouldn't, it has somewhat taken me by surprise. I've been asked what the biggest change I've gone through is. And, you know, I found myself giving different answers to all of those who asked.
I've changed a lot, and so I've told people, and even made the effort of making a whole blog entry about that (the User Manual, in case you haven't read it yet). I can hand you an almost endless list of how many things (some even barely noticable, yet still there) that have changed inside me. But what is the biggest change?

I was out walking, earlier tonight, when I realized. It was just a short walk, to go get some food, and yet it was a somewhat enlightening walk. The biggest change I've gone through is that when I'm out walking, instead of looking down on the ground, like I've done all my life, I am now looking up, and ahead.