1/Two years ago I quit a job I liked, with people I liked, to start something from nothing. I won't say it was the best decision of my life — that line sells a course, not a company. First thing I wish I'd known: the skills that got you promoted are worth maybe 40% of what you think on day one. Managing up, clean PRDs, reading a room — nearly useless here. The actual job is making something from zero with no inputs, and nobody trains you for that.

2/The first hire is a trap. Most founders bring in someone senior too early to "buy back time" and end up with a $180k/yr person who needs direction — the one thing you have the least of. Hire someone junior, hungry, who can ship without you looking over their shoulder. Or don't hire at all until you're personally blocked every single week.

3/Your runway math is wrong. You think "I have 18 months of savings." You don't. You have about 6 months of psychological runway — the window where you still genuinely believe this is going to work. After that, money still in the bank, you start making scared decisions. Ship to revenue or a real milestone before the belief breaks, not before the money runs out.

4/Everyone around a founder has an incentive to push you bigger — bigger market, faster growth, raise more, now. Almost nobody has an incentive to tell you to go smaller. The most useful skill I've found is the willingness to shrink the plan until it's something you can actually finish. Boring and shippable beats ambitious and perpetually half-done, every time.

5/Nobody is coming. Not your old boss, not your network, not the press, not the VC who said "keep me posted." In year one the only people who will care about your company are you, your co-founder if you have one, and maybe your first five customers. This isn't a bug. Build the thing where five people love it, and stop waiting for the world to notice.