Some will bring out the best in you, some the worst.
I truly, honestly believe that everyone you meet has something to teach you.
Just take a minute and think of the most amazing people you have met so far and how they helped or influenced you in becoming who you are now. Those people who complete your character, who make you want to do and be more. Who challenge you and make you ask questions. Who make you feel alive.
Now think of those who disappointed you terribly, maybe even more than once. Who made you doubt yourself, think you are not "good" enough. Who made you feel frustrated. And yet you survived. And from now on, pehaps you will know better. Or perhaps not. But at least you will know that in the end, you will get over it.
We need both the good and the bad experiences to get to know who we are, what we need, where we belong and with whom.