Okay kiddo, so there's a group of people who don't really like when other people play sports and wear those cool team jackets and stuff. They're called the anti-jock movement.
See, some people think being into sports and being good at them is all that matters in life. But the anti-jocks think it's not fair that people who aren't good at sports or don't like them as much get left out or made fun of.
They believe that schools and society put too much emphasis on sports and not enough on other things like art, music, or academics. They think everyone should have a chance to be appreciated for what they're good at, not just the jocks.
Now, this doesn't mean that the anti-jocks hate all athletes or think that sports are a bad thing. It just means they want people to have more opportunities to shine in different ways.
So, in summary, the anti-jock movement is a group of people who want everyone to be recognized for their talents and not just those who are good at sports.