The past does define you in some plain ways. It built your reflexes, your accent, the things that make you flinch. Pretending otherwise is its own trap, since you can't work with what you won't admit is there.
What it doesn't do is dictate. There's a difference between being shaped by something and being sentenced by it.
Most people carry one memory that still makes them wince years later. Notice that the wince is evidence of change — the person who did that thing wouldn't have winced.
Use the record as data about your patterns. Not as a prediction.