This was my third game jam I've participated in but the first I've ever actually finished and submitted.
The thing I learned most from this jam was that I should really be less anxious about showing people my game. I had finished my game and was considering not submitting for fear of people finding everything stupid. I eventually managed to say screw it and just submit the game because someone close to me said that whatever happens, whatever people say, they can always teach me more, and what I want to do is learn how to be better. Upon submitting I was pleasantly surprised by the amount of positive reception I got and it brought me to near tears.
More importantly however, I was shown issues with the game, simple issues I could have solved in 5 minutes. If only I had shown my game to others beforehand and had them catch it, then I could've fixed it. The issue with not showing your games or work to people is that it stunts your improvement. You can't learn from your mistakes if there is no one there to point them out to you. Moreover, if I had shown my close friends and family the game, they could have told me things to fix so that y'all wouldn't have to.
I really need to learn to get over that hump of anxiety and insecurity and just show my game to people, let em try it, and learn from what they tell me.