Crying in the Shower
When Square had a liquidity event in early 2014 someone1 shared their “crying in the shower” approach to investing with me:
Sell enough that you’re not crying in the shower if the company goes out of business tomorrow, but not so much that you’re crying in the shower if the stock goes up 100⨉ in ten years.
So I sold enough to become debt-free, and got fired shortly after that2. I bought up what I could afford in the following weeks3, SQ did make it to 100⨉ above my strike in 2021, and at no point was I crying in the shower over my investment decisions!
Best advice I ever got.