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.
Non technical gambling mistakes we can say such as what you stated.
For a worker it is interfere your work , for a student it is make you looks not smart because gambling is wasting time.
Regret why you did not take study seriously.
Worst mistake to get involve in gambling, put some funds and then it gone.
gambling have high risk since it design to make you lose money and much time.
Gambling is not 100 percent designed for a loser who always lost.
But I admit that only 2 person of 10 person who can make a good profit in gambling, the rest is losers.
Getting involved to gambling world is not worst mistake , it is just worst decision.
Worst decision I think is also equal of our worst mistake.
Gambling is really risky because every game counts every cent of our money.
People love risk but profitable at the same time, and for me gambling is one of it.
But if I were to choose whether gambling or investing. I would rather choose investing than to gamble.
Cause for me, investing is more profitable in a long run, while gambling can lose all your money in a short time.