According to yogic philosophy, we're born with a karmic inheritance of mental and emotional patterns—known as samskaras—through which we cycle over and over again during our lives.
The word samskara comes from the Sanskrit sam ("complete," or "joined together") and kara ("action," "cause," or "doing"). In addition to being generalized patterns, samskaras are individual impressions, ideas, or actions; taken together, our samskaras make up our conditioning. Repeating samskaras reinforces them, creating a groove that is difficult to resist. Samskaras can be positive—imagine the selfless acts of Mother Theresa. They can also be negative, as in the self-lacerating mental patterns that underlie low self-esteem and self-destructive relationships. The negative samskaras are what hinder our positive evolution.
But with mindfulness, right intention, and a lot of patience, you can turn your negative patterns into positives. The first step is to become aware of when you're falling into your habits.