I was bullied relentlessly for years. Even though I've long since been separated from them, I'm yet to fully heal the damage they did. I suspect a lot of my poor opinion of myself as well as my fear of other people is rooted in having internalized the abuse I took. Over ten years later, I'm yet to root it all out. Even now, whenever someone treats me maliciously, I find myself not merely hurting from what they did, but aching from the aftershocks of a lifetime's worth of abuse. I have a deep well of buried hurt and rage from adolescence, and when it's tapped into, I respond with a level of rage that seems to exceed the abuse that triggered it. I've had bullies at work tap into that and it scares me. I hate it.
Moreover, I have that little voice that says I'm a pathetic excuse for a person, and it does an exceedingly good job arguing against all my good traits. No matter what I say or do, it's there to cut me down. In a sense, I have trouble building any sort of self esteem because I am in complete disbelief at my own worth. I can tell myself I'm competent and likable, but I simply don't believe it.
On a positive note, since going back to school, I've had several of my peers shower me with complements, and even ask for my presence at events, both social and academic. While this hasn't erased the damage done in the past, this is helping to heal me, as it provides objective proof that what that sleeper agent says is bull----.