Why is it when something untoward happen to you, you'll consider yourself unlucky and others consider you careless? The reason for this behavior is what psychologists call fundamental attribution error. The phenomenon is all about placing blame on a cause you can't prove. According to the BBC:
When we observe other people we attribute their behaviour to their character rather than to their situation—my wife's carelessness means she loses her keys, your clumsiness means you trip over, his political opinions mean that he got into an argument.
When we think about things that happen to us the opposite holds. We downplay our own dispositions and emphasise the role of the situation. Bad luck leads to lost keys, a hidden bump causes trips, or a late train results in an unsuccessful job interview—it's never anything to do with us.
The only real solution is to recognize that your brain works this way. BBC suggests recognizing the behavior might be enough:
In more prosaic domestic moments, when it feels like such bad luck that I can't find my keys, yet my wife seems so careless when she can't find hers, I know I'm performing psychological magic. I'm observing the myriad events in the world and imagining things—my bad luck, her carelessness—which I use to explain the world with.
Psychology Today offers one possible experiment you can do on yourself to check yourself for this behavior:
[T]he next time you find yourself being cut off from your lane as you are driving (or something similar happens), notice the nature of your spontaneous interpretations: are they negative or positive? That will give you a clue as to whether you have scope to become less cynical.