Rejections are wonderful sources of motivation
It’s not news to anybody that people use rejections to motivate them to prove people wrong, better themselves, improve their work, or whatever. However, not everybody do. A lot of people just look at it as that they, or their work, is plenty good enough, and it’s those doing the rejecting is wrong. They’re then insulted, angry, maybe plotting revenge, etc. Motivation is not at all what they take from it, whereas I’m suggesting in this sweeping statement they should take it as motivation and not care whether those rejecting are right or wrong.
As for those who take rejections as motivation, they usually embed it in anger and/or ego. “Rejections are a wonderful source of inspiration” is not often the first thought they have. It’s a lot more personalized than that, like “well, I’ll prove (so and so) wrong”. But I think it’d be more effective if they just skip that step, which some people never get over, and go straight to using rejections purely as motivation. The anger can, and will likely come out, when the adrenaline is required for those tough moments you’ll need to overcome to prove them wrong. It doesn’t need to be wasted at the start.