When Cory Matthews began exploring this great big world, a generation of TV viewers were changed forever. And the recent cast reunion of “Boy Meets World” is a reminder of that.

The show, which ran from 1993-2000, followed a teenage boy whose curiosity about life leads him into some hilarious adventures while growing up alongside his friends and family.

Four actors from the ABC sitcom were seen in Boston this weekend, while they were in town for Comic-Con Fan Expo.

Ben Savage, who played Cory, posted on Instagram a photo of himself with co-stars Danielle Fishel, Rider Strong and Will Friedle. And Friedle shared a photo of the group with one of their other beloved co-stars: Williams Daniels, who played the Matthews’ family neighbor and stern teacher Mr. George Feeny.

The excitement around the reunion has some now-grown-up adults reminiscing on their memories from the ’90s.

Here are five lessons “Boy Meets World” taught viewers.

Growing up can be hard (even on TV)

Becoming an adult isn’t as easy as it looks. Cory had many heart-to-heart conversations with his dad during the series. From girls to friendship to owning up to your mistakes, viewers saw Cory face the good and bad moments of adolescence.

Never underestimate your teachers

Even when his students thought they had outsmarted him, Mr. Feeny was always two steps ahead of their schemes. But he wasn’t just a strict teacher. He was a mentor to his students who helped guide their moral compass.

Eat what you want, when you want it

“Boy Meets World” didn’t shy away from real-world topics like body image. In one episode, Topanga Lawrence eats a slice of pizza as her friends fear what it may do to their bodies. She begins to question herself, but Cory reminds her that her confidence is what makes her the beautiful person she is.

Blood doesn’t have to define your family

Shawn Hunter wasn’t Cory’s biological brother. But the Matthews family treated him like he was one of their own and even offered to adopt him. While he declined, Shawn did ask Alan, the patriarch of the Matthews household, to yell at him like he did his sons Cory and Eric.

Don’t let a relationship change who you are

The friendship of Cory and Topanga showed viewers the value of not changing who you are to fit better into someone else’s life. Topanga, a witty and ostracized teen, accepted Cory, an overly curious and caring boy, for who he was. Their friendship, which later turned into a marriage, was the show’s overarching example of finding your special place in the world while being your true self.