Well worst mistake would be to invest too much time and resource to gambling. Let's face it gambling is a game of chance, there's no guarantee in gambling so making a bet that would either make or break you financially and emotionally would be a very big mistake
Something we all regret. I also never gave any importance to my studies as a student due to gambling ( non btc ) and now regret why i did so. Anyways I have a settled life so yeah when I look back, I feel that was my biggest mistake.
I think it is okay because you are now moving on and matured enough to think your mistakes before, and we can really learn from our mistakes in the past. And now that you have a family I think you will do everything for them and work hard for them like what I am doing now for my family, even if I am not a manager or have a big position in a company at least I can handle everything and our daily budget..