“It is hard to fail, but it is worse never to have tried to succeed.” – Theodore Roosevelt
Failure sucks, but not as much as the regret for never having tried does.
Being told no by the client is better than having never asked, because to get in the position to even get an answer you had to improve, to plan, to overcome your fear and ask. The “no” is not great, but you are better than you were merely from doing what is needed to ask for the business.
Your crush probably won’t laugh when you ask them out. Even if they do, you are better for having the courage to step up and try.
DNF a marathon (Did Not Finish)? You still improved over the months of training. Yeah, failure is a kick in the gut, but you are stronger than the person still sitting on the couch. The pain will fade but the lessons won’t, and next time around you are an improved version of yourself because you were in it instead of a spectator.
Have the courage to fail, because that is the only way to succeed.