I say screw it. As long as you're not being an obnoxious d-bag or breaking the law, people are either going to see you for two seconds (as our easily-distracted attention spans like to do) or they'll look at you having fun and enjoying life and wonder to themselves why they can't do the same, causing them to re-evaluate their own life so they could have fun as well. On the outside it'll look like judging, but on the inside they're studying.