When we are pleased with ourselves, we tend to express it and share it. We like to accentuate what we think are our best features. For example, a woman puts on bright red lipstick when she is pleased with the shape of her mouth, or another woman wears a wide belt to accentuate a slim waist, or a girl wears her dresses short because she likes the shape of her legs.
The same thing happens with our skills and abilities. We go to college or university to advance the skills we believe we already have. If we are good at mathematics, we might study math; if we like to write, we might study English literature.
Conversely, we try to hide the aspects and features of ourselves that we do not like, or we think are weak. A woman might wear a long skirt to hide her bandy legs, or another woman might wear her hair long to cover up her ears that stick out from her head. Someone else might wear a cap to hide a balding head.
So we tend to express our strengths, because we exercise them daily. On the other hand, we tend to hide our weaknesses and keep them locked inside. So we do not talk about them and keep them inside, adding to the secret stash that builds up over time.
This is why it is important to sometimes let them out, like when we laugh at a comedian expressing the very same weakness that we know we, too, have. We can also deliberately let them go by putting something better in their place.
It is important to know oneself, so that an unexpected burst of anger or a bout of anxiety does not take us by surprise. When you know your weaknesses, you can work to eliminate them, by chipping away at them one step at a time. So, for example, a person who tends to be impatient might deliberately set out to be patient on a particular day, or someone who is stingy might deliberately decide to give something away on a regular basis.