Naivety of believing all the lies you’ll be told about your equity (if any!) in order to justify you working 80 hours a week for a shitty pay and massive tech debt, when you could just go work at Google (or similar) and be treated like royalty while learning how to write proper software.

Source: started my career in early stage startups, now at Google. I even got lucky to have made a couple bucks from my equity (so I am a massive outlier, statistically speaking), but it still wasn’t worth it.