Secrets (Totally random)

I have been struggling with the meaning of Secret or secrets. What is your definition of Secret? Why is a secret all most always a bad thing? 

se·cret

ˈsēkrit/

adjective

1. 1.

   not known or seen or not meant to be known or seen by others.

   "how did you guess I had a secret plan?"

   synonyms:

   confidential, top secret, classified, undisclosed, unknown, private, under wraps; More

noun

1. 1.

   something that is kept or meant to be kept unknown or unseen by others.

   "a state secret"

   synonyms:

   confidential matter, confidence, private affair;  skeleton in the closet "he just can't keep a secret"

I was talking with a friend and it turns out we have a totally different opinion on the meaning. Ken and I seem to be on the same side of the meaning. I guess that is why we are married and tell each other almost everything. I have always assumed that everyone has something that they keep to themselves and I consider that normal and healthy. But when or how does that become unhealthy. Where is that line drawn? Okay last question is a Secret then a lie if you never disclose or talk about?

I have been trying to find something to help me under stand all of this. Bible versus, Self-help books, blogs, websites and so on. So far I am just even more confused. I would love to hear what you all think.