Let's focus on the not so serious things.
I've heard a lot of people say Star Wars changed their lives. On the surface it sounds crazy, but I totally get it. JJ Abrams has said this and last I checked he was doing pretty good.
I think I've had a few things in life that have changed my path and made me a person that I would not have been otherwise. Star Wars is on that list, as is Marvel Comics.
Though when I think of music, I can still remember specifically a particular song and video that changed me forever. It made me realize that there was more to music than what the radio played me and it made me curious about what else was out there. Because of this weird little song I went on to find The Clash, the Ramones, the Sex Pistols. Which led to Minor Threat, Black Flag, the Misfits. Which led to Funkadelic, Run DMC, the Beastie Boys. Which led to Nick Cave and the Birthday Party, DEVO and so on and so on... til eventually I said, "hey, I want my own band!"
Funny, I wonder where I would be and what I would be doing had I not turned on the TV and saw this!