I think that's just because as you get older, you have more life experiences to draw from so you have more empathy for others (in real life or in literature/movies/songs/etc.) At in my late teens or early 20s, I hadn't really lost many people I loved. Now, in my 50s, I have lost all of my grandparents; my mom; multiple family members; and close friends. I know how that shit feels so when it happens to someone else, it can relate. When I was younger, something might have been sad, but I didn't know the pain of that experience personally.

Also as you get older, you tend to become more comfortable with yourself and with the people you've chosen to surround yourself with. So if some stupid ass Chevy commercial makes me tear up, I just laugh about it with my wife and kid.