I read The mistakes we make the second time by Harry Glaser. It points out that certain things are easier than they should be (raising money, hiring) and that friction is helpful. It’s easy to build in anticipation of scale you don’t have because you weren’t spending enough time getting to product market fit. It also talks about how the excitement and joy don’t the same thing they did the first time (e.g. seed round doesn’t feel like an accomplishment).
I’ve started a few companies and it’s easy to over correct based on prior, often painful, mistakes. It can be difficult to recognize the biases we have and the scar tissue that led to it. One thing I try to remind myself is that the number one job of a startup CEO is finding product market fit and to make contact with reality often.