Except that's the Harold and Maude song! Yes, Cat Stevens' did the soundtrack for this movie in the 70s that's a "classic". I know this because I was at the video store with my parents a few years back and Dad brought it up, I said I'd never seen it. He was like, "You haven't? Oh we're getting this, everyone's seen Harold and Maude!"
It's about a nineteen year old boy who's obsessed with death and being weird, and he falls in love with Maude, who's in her 70s. It's sort of disturbing. Funny in a dark way but the whole 50-year age difference is so wrong. I watched this with my parents then was like, "Dad that movie was messed up!" He's just like "I know! Never said it wasn't. But now you've seen it!" Or something to that effect... he didn't make me see it to be mean or anything, it was just funny that he admitted to knowingly picking out a movie that was kinda weird.
What? So anyway that's why I'm sort of scarred for life every time I hear this happy little freedom-loving hippy song. And now you are too. Think of someone your age making out with a septuagenarian when you see that commercial, just for me. I suppose the movie is supposed to be about acceptance and life stages being relative and being open-minded and learning things... or it might just be about how to shock people. Either way, it's weird.