The mentor who gave you hours for free was investing in you. Pay the dividends by getting better.

Somebody spending unpaid hours on you was making a bet. They gave up evenings that could have gone anywhere, on the theory that you would do something with what they handed over. The only thing that ever settles that debt is you actually getting better at what they taught you.

Pick one correction a coach, teacher or boss gave you and work it this week until it sticks. Then tell them it landed. People who teach rarely find out whether any of it took, and hearing that it did keeps them doing it for the next person.