As a kid, I was first introduced to G3 but I thought it was too "girly" despite being a girl myself. I was also pretty indifferent to G4 since I'd just see it on TV in passing. It wasn't until I decided to rent Equestria Girls that I truly got interested in the show, which I know is a weird way to start!
What else is funny is that once I actually started watching all the G3 specials, I grew to really like it! Now that I'm older, I like more cutesy and simplified things since it's a nice break from the real world.