A little boy was told by his father, from a young age, that he wasn’t good enough. Not in so many words, but through his actions — by criticizing him, yelling at him, hitting him, leaving him.
The boy grew up into a man, knowing that he was unworthy of praise, of success, of love.
The boy, as an adult, got a job, but didn’t really think he was good enough to do the job well. He faked it, deathly afraid every single day that he would be found out and mocked, then fired. He tried to hide, not to put himself in the spotlight, because then maybe no one would see his unworthiness.