This is the earliest prolonged episode I can remember, and I'm not 100% sure it was hypomania, but here goes:

Summer 2013 was an amazing time for me. I started that year depressed and anxious, but come late spring that anxiety and depression vanished and I suddenly became much more outgoing, adventurous and talkative and started taking on a bunch of hobbies. The biggest event of that summer that makes me believe it was really hypomania was when I decided to go across the country by myself to visit an online friend. Normally I'm too anxious to even go to the store by myself, let alone go across the country. Anyway, I was planning on taking a two week long train ride there so I could "hear everyone's amazing stories" on the way there. My parents had eventually talked me out of it and I had settled for a plane ride instead. That was a good trip even though I said a lot of things I wish I hadn't.

The rest of the summer was spent taking lots of photos of the amazing world and spamming facebook with stupid updates as if I was the most popular person in the world. Come early fall, I had a total meltdown. I tried to erase all traces of my name and face in the house for some reason. I took sharpies to pictures and ID cards, and violently "rearranged" items in the living room. Eventually I became suicidal and ended up in the ER, somehow narrowly avoiding a psych ward stay.

After that mess, I saw my pdoc who told me she was suspecting bipolar, but didn't want to commit to a diagnosis. It wasn't until a year later that I was officially diagnosed during neuropsych testing.