Ah, nostalgia. It’s the unavoidable memory of something from your past that strikes you unexpectedly and makes you feel warm inside. Usually this applies to positive experiences — but sometimes it can be painful to remember old times in your past when things weren’t so great. I was thinking about my childhood the other day and all the wonderful memories I have. I was born and raised in New York City, but grew up in a small town where everyone knew each other. I remember spending lazy summers days down by the river with my friends, fishing and swimming. We would get lost in the woods, explore abandoned houses, and…