Rejection is incredibly difficult to deal with. I suspect some people will say they are immune to it, but (anecdotal example) I've been rejected from hundreds of jobs over the past 3 years and every one hurts a little. I felt it never got easier to deal with rejection, but it got easier to interview and move on.
Perhaps it's not the rejection, but the energy in creating the next steps I need to take (more resumes, taking classes, new career, therapy, etc).
Perhaps it's not the rejection, but the energy in creating the next steps I need to take (more resumes, taking classes, new career, therapy, etc).