Hi Lychee,
Perfection isn't a human trait. It would seem we can learn from perceived errors in judgment, wouldn't you agree? What did you gain from past errors?
Why not reflect on the emotions behind your track record. Consider the feelings you may have associated with people in the past and what you learned about your instincts and intuition. Did you base your thoughts on heresay, your observations, personal bias or suspicion? What you learn and retain from the past will help you sharpen your instincts in the future.