Well done for sharing your mistake. As you have learnt a lesson and shared it here, others will learn from it as well. It is sometimes very hard for others to admint their mistakes because of pride.
Yes you didn't learned a lesson if you didn't make mistakes in your life. You're corect some people they can't accept there mistakes cause of there pride they always thinks there always right. For me my mistake is my guide to change my life to become more better person.