This means that when people feel threatened or insecure about your current success or progress, they may try to diminish your achievement by reminding you of past mistakes or failures. It is a way for them to feel better about themselves by undermining your confidence. Those who are strong and skilled are not bothered by these kinds of personalities. They are haters because they are losers. Let them die in envy , they will miss many good opportunities. Instead of attending to your success, they'd better find their paths to improve their statuses.
True talk! Some people just can’t stand seeing others happy. When they see you living a good life, they start to act funny. I’ve experienced that before with a friend of mine. He even stop greeting me because I got a new phone. I just laugh because life is not suppose to be so bitter like that. Jealousy wastes your energy to be frank. So, in that case , I’ve learned to distance myself quietly from such people because I don't want negativity around me.
Jealousy and envy kill. They are like a deadly disease hard to cure, and only themselves can cure it by changing their mindsets and accepting their fate. Some of these types commit murder because they do not like to see someone better than them.