Our first mode of communication with the outside world was crying. The first essential cry that makes breathing possible that leads to a switch for the baby from the mother's womb to the world full of strangers. This cry is genetically coded as a behavioral pattern, which is essential for survival. Soon, the behavior of crying is repeated by the baby whenever it needs attention, be it for feeding or for wanting to be made comfortable. This makes crying the precursor of all forms of language i.e., to say that language itself then evolved from crying.
As adults we cry when we are in pain which could be physical or emotional, or when we experience extreme happiness. What if I tell you then that when we cry we go back to those pre-medieval times when language has not been born yet, but babies were being born. Sounds were are only means of communication and those ancient patterns are ingrained deeply in our brains.
Crying signified a way to link memories of horror with hope of survival. Imagine, a rain being triggered inside the brain to siphon off all the negative memories and press a reset button. Because that first cry was the biggest stress that an individual can face in its lifetime therefore, it has to be linked with the following:
1. Create a sense of well-being
2. Wipe off the negative memory
3. Bring comfort and hope
4. Trigger feeling of security
So, in short crying is rebooting your brains to achieve the same, which you would do to reboot a frozen computer.
When you feel too overwhelmed with emotions, the brain needs to be saved from using too much energy in trying to make sense of all that is going on.
When you feel an imminent danger approaching, you again need to conserve energy to prepare yourself.
When you get hurt physically or emotionally, the brain gets again into that mode of self reboot to focus on the healing instead.
Then, crying isn't just an act of expressing emotions or words that at times become difficult to be expressed because it would take too much of brain energy to make it possible, since the brain wants to conserve energy it instead goes onto the re boot mode.
Saving energy, protecting itself and creating a sense of healing that is what crying reboot does to our brain. That is why crying isn't bad. Crying doesn't signify you are weak.
Unless of course it gets triggered by rubbing of your thumb and index finger like happened with this old man, then you definitely need to get an MRI done as soon as possible!