Some of my fondest memories as a child was trick or treating with my best friends and I miss it a lot. I personally stopped going trick or treating when I was in middle school because all my friends "grew" out of it. No one would go trick-or-treating with me so I forced myself into thinking it was a dumb idea to go out, but I continued to dress up and have parties. I wish I had kept trick-or-treating, I loved walking around and looking at all the houses and getting candy and dressing up. I applaud teenagers that still go out trick or treating and dress up.
Every time I had a Halloween party it was "costume optional" and it seemed like I was always the one most dressed up. It seemed like as people get older they throw away the thought of dressing up unless it's something sexy to attract guys and the guys just stop dressing up. I don't see why it's a bad thing to let out your childish side and dress up on Halloween, and of course wearing a sexy costume still counts, I'm not dissing it. But letting loose and having fun getting all dressed up with friends makes me so happy. There are such rare occasions that teenagers, college kids, and adults can relax, why wouldn't you take advantage of that? Halloween is just one of the holidays that we get to have fun.
So this Halloween lighten up and dress up. Don't think your too old or it's too silly and just try to stop thinking about what others think about you. Get together with your friends and come up with group costumes or just great costume ideas in general. Throw a Halloween party, get excited about it, decorate the house, make Halloween snacks, get lots of candy and just have a good time. Don't let age or other people tell you what is or isn't a good time.