There could be so many ways to look at this. But first, I want to say that it's fantastic that you’re reaching out, and it sounds like you are still actively tackling this heck of a challenge called life and want to work through dealing with its downs. That effort and spirit in itself is commendable:)
One reason could be high expectations we set ourselves, perhaps from external pressures, or simply because we don’t see (or willingly ignore) the many many times other people “fail”. I myself struggled with this for ages—I didn’t realise that I took the quote “do it once, do it right” quite literally (not that I actually did that, but that became an expectation) until someone pointed out that I was a perfectionist years ago. And despite that, old habit dies hard, it’s still frustrating when I feel like I couldn’t meet the standard I set for myself (standards that actually require tons of practice/a longer path to meet), or even the “reasonable” standards others set for me, although I thought I was at my 120%. Because well, everyone have their own paths to walk, and my weakness might just be everyone else’s strength.
What helps, is realising that it’s unreasonable to expect “success” every time we engage with a task. “Success” generally requires 1. a good understanding of what the task expects from you (e.g. knowing the scope of an exam; knowing a company's application criteria) 2. the right strategy (e.g. a study method that works for you; having a well-crafted resume/prepared for possible interview questions) 3. Practice & effort over time! (e.g. going for multiple job interviews to gain experience; consistent studying and doing mock tests)
And most importantly, understanding that each “failure” is not a failure, but a step closer to our goals. Because we can learn something from EVERY experience. This is not me simply saying “to “look on the bright side of things”, but really, every experience is valuable even if it’s not what we wanted/expected. I personally learnt more about my career preference after a long summer internship that “failed” because I was miserable all the time—I now have 1 more thing to look out for the next application round; I learned about my weaknesses in Chemistry after failing its exam many times—I could then identify loopholes in my understanding and consult my teachers, and since that subject really isn't my forte, the experience also taught me how to learn other difficult things I come across in the future; I learned about the extent and power of my resilience after “failing” on so many levels battling with mental health—I’m now more ready for the next fight if it happens again. You see where I’m going with this?:) So don’t be so hard on yourself, you are actually always making small progress. Small, but not necessarily insignificant.
A word of caution is that learning these doesn’t mean you’ll “succeed” the very next time (remember time+practice?), but it’ll definitely take you closer to unleashing your full potential, and your ultimate goal!
Lastly, I’m not sure under what context you asked this question, but please remember that not achieving something doesn’t define you as a person. These are simply trips/falls/barriers in the long journey ahead!
I’ll stop here bcos it’s a wall of text already:p but all the best!! xxoo, Amber