I love Halloween - closest thing we get to a seasonal thing. I live in the land of sunshine and 70 degree temps on Christmas, so Halloween signals the change from summer to not-summer-for-awhile. It also is the closest thing to a religious holiday that we celebrate at our house, and is the signal to do a lot of things in the garden (feed cymbidium, plant cole crops, pull out first season tomatoes, prune trees, etc.) It marks the years for me, just as the Spring flowering of the fruit trees.
I also like the costume aspect. KTC, I feel badly for your experiences in high school - remember, many of us had nightmare lives then, too, it's part of what makes us writers - but having one day set aside to dress as you wish you could be is a gift to many of us. I loved my Star Trek uniform, my witch's costume and that cute Sailor Moon outfit - I wore them all to work, just like in my fantasies!
And the candy - I am diabetic, so I can't eat any of it, but I love giving it out - it's one time when I can stand in my driveway, give out something nice with a smile and be delighted in return. I really love this time.
.