Adopting the growth mindset in lieu of the fixed mindset. I was unhappy with my abilities and used to think, "I just have poor memory", or "I have hit my maximum ability" etc. But somehow somewhere I realized I can work hard to actually improve and change those things, and that they are not fixed.

I came across the concept of growth mindset a few years earlier and has since strengthened my commitment to adopting a growth mindset. I would recommend reading "Mindset: The New Psychology of Success" by Carol Dweck.