I went to a Christian school from K-12, then again for college, and didn't have a really secular job until this one. I've been saturated.
Now I'm surrounded by non-Christians who look at me going about life as I always do, not always strong or hopeful or non-depressed... and they still want to know, "Why are you happy all the time?"
It's not something I normally think about. It's just life. God is in my life and He (obviously!) makes a difference that can be seen, but He's always been there and I don't really have "pre-conversion" memories or confessions or dramatic stories. And I've never been all that different from those around me, because they all had Him too. These co-workers make me see Christ in myself, if that makes any sense. They force me to step back and go, "Wow. I'm not normal. I never thought of myself as being anything extraordinary, but I stand out to these folks and it's all because of God. He's working in my life. He's using me to show them something different. That's awesome!"
And I think that's important. That it's too easy to take the presence of God for granted. Not even that I would take credit for His doing, but just that I don't acknowledge the difference He makes. It's good to see.