Are most of your thoughts positive or negative? Do you find yourself spending more time worrying or counting your blessings? Are your parents or teachers too hard on you, or do they just expect great things from you?

How you perceive yourself and the things happening around you can greatly affect your reality. For example, if you constantly tell yourself that you are no good at math and that there’s no way you’re going to pass, well, then you probably won’t. However, if you treat a difficult subject like a challenge that will improve you if you work hard at it, you’re much more likely to succeed.

The key is your attitude, and the source of your attitude is your philosophy, or, rather, how you view life and yourself. If you want to change certain parts of your life, take a look at yourself first. Start with your attitude. That’s what 19-year-old Tameka Crawford had to do when she got to college. She changed her attitude about herself, and that simple choice changed her life.

Tameka lived in a foster-care group home, and she was insecure and scared about going to college. “I worried about people finding out I lived in a group home and treating me differently and making fun of me,” she says.

After she got to college, it wasn’t long before Tameka started skipping classes and letting her grades fall. She figured she had plenty of time to pull her grades up; she began creating excuses for herself. “I found myself using the excuse of being in foster care every time I missed a class or failed an exam,” she says. “A lot of times I would say to myself, ‘Oh, I live in a group home. Who cares if I go to class or not?’ ”

Tameka admits that even though no one was treating her differently, she still perceived they were. She put limits on herself because of her background. Soon, her self-esteem was low and her grade point average dropped to a 1.0.

“I felt nobody cared for me,” Tameka says. “I didn’t have any family support. I kept making the mistake of comparing my life to students who had parents calling and visiting them.” Just before the end of her first semester, Tameka realized she was wasting time feeling sorry for herself. She got tired of using foster care as an excuse. She was tired of failing tests, and she was tired of crying. “It wasn’t because I was in foster care that I was failing my classes,” Tameka says. “It was because I had been paying too little attention to my schoolwork. It wasn’t being in a group home holding me back—it was me holding me back.”

Tameka knew that she needed to change her attitude toward herself before anything else would change, including her grades. During her second semester, she began attending her classes regularly and studying hard to pull her grades up. She sought help from tutors and her professors, and even went to counseling. She started to depend on herself and discovered what she was capable of.

By changing her attitude about herself and her past, Tameka put herself on a path to success.

What we think of ourselves has a tremendous effect on our lives. Fill your head with negative thoughts and you will probably be a negative person. Keep a positive attitude and you’ll most likely have positive things happen to you. It’s your choice, and while it might seem like a simple one to make, it can have powerful results.

Sponsored by the SUCCESS Foundation and adapted from the book SUCCESS for Teens.