I guess like 99% of people doing this business shares the same feeling with you. This is in the nature of this business and at some point we all do the same so called 'mistake' and sell stuff early. Or even sell late sometime. This is something we can learn from. Patience is the key if you really trust a coin.
Also sometimes we could be in a need of cash and we sell our precious coins as soon as they increase. All these stuff happens and we can't do anything.