Mahabharata is a source of inspiration for anyone and everyone who is at the crossroads of life. The situations and incidents narrated in the epic are such that everybody can relate to. The largest epic that consists of 100,000 shlokas in its current circulation, offers many more than 100,000 advises. But not everyone can infer the deeper meaning of these shlokas.
One has to be able to go beyond the text and dig a little deeper to get the hidden inference sometimes.
The shloka goes like this:
Striyam Mudhen Baalen Lubdhen Laghupani Va
Na Mantrayit Guhyani Yeshu Chonmaad Lakshanam
It talks about six people whom we should never share our secrets with. They are - a woman, a child, a foolish person, a crazy person, a greedy and a wicked person.
People who have no sense of time and place can be termed as foolish here, and who might end up saying unwanted things at a place where it is totally unsafe. It is always safe not to share secrets with such people. They might anytime let the cat out of the bag at an inappropriate moment and put you in trouble at an inappropriate moment.
Similarly, if by mistake an insane person gets to hear a secret, he might end up saying it aloud or at a place where it is unsafe.
A kid has little knowledge of right and wrong. They lack the maturity to make out what might cause a problem to the other person. However, their innocent hearts might go and spill out the beans about a matter based merely on hearsay. So telling them some secret is obviously not safe.
A greedy man has greed as his weakness. However close a friend he might be for you, but there is no assurance they would not betray you. Once they know your weakness, they might forget all the promises made not to reveal it before people, and would give up on the friendship due to their greed. Hence, one should never tell them what has to be kept secret. A wicked man can exploit you for their own selfish motives anytime.