Investors don’t validate your startup — users do.

You don't need every investor to like what you're building. You just need a few of them to believe. The reality is that no matter how great your product is, how much traction you have, investors are going to reject you, and that's okay. In fact, it puts you in great company.

Here's a great example: Envision. Envision is a medical device startup for cancer detection, and it was started by Sir Bisarna, who's a YC group partner. Today, when Serbia started building Envision, she was rejected more than 50 times by investors to just get the first money for the company.

The way that she was able to convince someone to write that first check and to help her get this company started was she told them she was going to bet on herself and take no salary for the first two years if the investor was really into betting on them. That was for a $25,000 check.

Her first round of funding for the company was only $500,000, but she got it done even though she got rejected over and over again. Since then, the company was acquired for $275 million.