Founders often ignore the advice of YC Partners about mistakes they are about to make, and they come back later wishing they had listened.

Seeking a co-founder just to fill perceived deficiencies or to check a box for the YC application is a bad idea; founders should try to succeed on their own first.

The YC application process emphasizes the importance of clearly expressing your startup idea to avoid missing out on opportunities.

When applying to Y Combinator, the midwit founder tends to overthink the application process, seeking excessive feedback and recommendations, while the successful founder simply fills out the application and submits it quickly.

Many founders applying to Y Combinator are unaware of the full extent of the program's offerings, including ongoing support after the initial three-month period.

After getting into Y Combinator, we made early-stage mistakes by hiring without proper culture fit vetting and dreaming too big without focusing on execution.

Many startups make common mistakes, but exceptions exist where some have succeeded despite them; however, minimizing these mistakes can improve your chances of success.

When founders receive wrong advice, they create a flawed mental model of the startup world, making it harder for them to unlearn those misconceptions later.

Founders frequently share horror stories about their fundraising experiences before joining YC, highlighting the stark contrast in investor behavior and terms they encounter after participating in YC.