In short, get rid of them!
When you have beliefs, ideas, or impressions that curtail your own emotional development, you are committing a true act of cruelty upon yourself. You're hindering your own progress and putting roadblocks up in the way of your own happiness.
Self-reflection can be an important part of growing up, no matter what age you may be. Try getting out of your own comfort zone from time to time. Dip your toes into new and unusual places -- it may be exciting or even frightening, but it will definitely expand your mind and show you cool new ways of living and thinking.
When you remove your old, limiting ways of thinking, you are opening yourself up to wild new possibilities for happiness and fulfillment!