Handling rejection in a constructive way is a crucial life skill
Rejection, and it’s close relative, disappointment felt at having something you’ve worked hard on rejected (which aren’t *exactly* the same thing, but close enough for comics), are an inherent part of science and academia. Peer reviews and grant reviews and just the SCIENTIFIC METHOD ITSELF are all really great at making you feel low. A critical skill in science, academia, and life is how to parse rejection, accept the parts that need to be accepted, and build from those parts to bring you and/or your work to a higher level.
What would science be without hypotheses that could be rejected (hypotheses that may have taken a great deal of effort to arrive at, I might add?) Confirmation bias.