This is the best lesson I learned after launching my business. Not only is it important to learn from failure, but it's also important to normalize it. In my lowest points I would reach out to my other self-employed friends and they would all remind me failure and hearing 'no' is 90% of the job. At some point you'll hear 'yes' and can move forward with that. But to get there you need to wade through a lot of 'no'.