I'm sure many of them will go over my head but have you posted a question or answer on MathSE that you were really proud of, and if so what was it?
I recently just had my first question that, and I may have been looking in the wrong places but, I could not find anything on via Google & MathSE which was: How to tell when a degree sequence has a unique unlabelled graph
I was just so surprised to not find anything on what otherwise seems to be such a simple (at least simply worded) question. Between providing the context of how this question popped up for me, having some solid understanding that there are cases but unable to find the key/pattern to when the answer is true, and the awesome answer that was given. The whole process has brought me so much joy.
This just feels like such a big milestone for me because I would say my experience on MathSE has otherwise been the complete opposite. Typically my questions, coming from some problem from an intro class I am taking mixed together with my terrible mathematics foundation, tend to, mostly rightfully, be not well received. But for a while it has led me to become overly worried about asking too elementary of questions which is hard when taking such intro classes sometimes.
This coinciding with me very recently being able to actually contribute my first MathSE answer must be a sign. Hopefully one that means there's plenty of good questions (and answers) to come from me which I honestly never expected. I am so genuinely happy though right now haha.