First startup job in the dot com era, employee #30 at a pre IPO startup. Started same day as another guy I will call Steve. I got a nice stock grant but didn’t

First startup job in the dot com era, employee #30 at a pre IPO startup. Started same day as another guy I will call Steve. I got a nice stock grant but didn’t really understand it so I bought a few books and read up on options and AMT. Two years later and we are a public unicorn. I carefully exercised my options and sold my stock, keeping track of my taxes and paying an accountant just to be sure. Steve exercised his, held the stock and rode it down in the crash. Ended up completely bankrupting him, he lost everything due to a massive AMT bill. He’d used H&R Block to help with taxes and back then they had no idea about AMT. One thing I will add - I did fine but if I’d known about ETFs back then I’d be a lot wealthier. Don’t make the mistake of trading actively and especially don’t make the mistake of investing your tech gains in more tech until you have diversified enough that you don’t care if you lose it.