Nobody holds on to a winning lottery ticket that long. You cannot exit at the top and trying to do so will drive you crazy.
I think you and your friends were right. I had a coworker that was selling his stock as fast as he could and it finally dawned on me that he was doing the right thing. When you work at a place, you are investing your time an energy into an idea. If you hold stock in that place, you aren’t diversified.
If the stock tanks, layoffs are more likely to happen. And then you are broke and jobless. There are very few companies you can work for where your own stock is the best bet on the stock market, and second best is often pretty darn good. Gamble on a different income stream.