Honestly, childhood.
I've struggled with mental health for most, if not all of my life. I was your stereotypical "good kid". You know the type that always reads, makes straight A's, never argues, does what they're told, and never speaks. I was only that way because I realized early on that no one cared what I had to say. I saw how I was always doing chores while my sister got to go hang out with her friends or while my brothers did whatever they wanted. If I wasn't doing chores, I was reading. But the most memorable time was when I was 15. I'd gotten an honorable mention for my story "The Lonely Girl and the Stars", and when I tried to express my feelings over it, I was quickly drown out by my family who talked over me and ignored me. I faded into the shadows on the front porch and went to my bedroom. For me that was one of my biggest moments in life. My first real achievement. And my excitement was squashed by a family who couldn't be bothered to listen for two minutes. I did get to celebrate with my parents but not after begging to go to the awards ceremony that they didn't want to go to.
The second most memorable incident was at my graduation party... I had a huge part of my family there and my two best friends at the time. One of my best friends had to leave early for her own graduation (which is fine, that is understandable). The second had some assignments to do (she was a junior). After they left no one else spoke to me the entire time. All those people were supposed to be there to celebrate my graduation and yet couldn't be bothered to acknowledge me.
Both times crushed me, but it taught me that my family doesn't care that much about me, if they can't be bothered to acknowledge my successes. While, I do believe they love me and care about me, I also know I could do everything right and never get a nod of acknowledgement from them unless I point it out. They also taught me, I'd rather be alone and celebrate myself than be surrounded but ignored.