A secret is something kept from the knowledge of others. Also, it’s shared confidentially with people that we trust. Once we share it, we also repeat to our confidant “Don’t tell anyone”.
When we told someone not to repeat something to others it becomes an obsession for him. Generally, the confidant is not involved in the subject. So, he’s incapable to keep it for himself. Since almost person have a confidant, it’s very likely that your confidant will share what you told him with his own confidant
So why we share our secret if it’s so obvious that they will get out?
Getting close to your friends
Some people find telling their secret to their confidant a way to be more close to them. But linking how close you are to your friends with sharing or not your secrets with them is not a positive behavior. You have to understand that you can have close friends without telling them your secrets.
Another reason is that keeping secrets from our close people makes us feel often guilty. This feeling is usually close in our minds to the fact of losing or gaining the trust of our close friends or family.
Challenging your capacities
Keeping a secret requires constant effort. Secrets are like bad thoughts, more we try not to think about them more they tend to occupy our brain. Which leads to end up revealing the secret.
The character of the confidant
Sharing a secret with a person who talks a lot is always a but idea. He can involuntarily let it slip out. Also sharing our secrets with a quieter person can cause him more stress. Thus, to relieve himself, he finally won’t be able to withhold what you told him.
Finally, as a solution, you can write your secrets in a journal instead of sharing them with others. It will make you feel some relief.