Hopefully you've accepted these as valuable lessons to help you deal better with people. Not as reasons why you won't hire certain people. You can't ignore what you have learned, but you can't apply it to everyone either. There are employers who will not hire people of certain ages because of bad experiences. What it comes down to is they base their hiring decisions on their bad experiences.
Every person is different.
So even if you have had a bad experience with, as an example, a person with red hair, don't let it keep you from hiring any people who have red hair. Focus instead on what good things you've learned and use them every chance you get. As an employer, you look at a person's work experience and work related references to tell you if that person can do the work. This is important. It's important for you to learn if a person you are thinking about hiring has a bad Work History.