One commentary explains that the enslaved Israelites had feared to sigh or cry, because their ruthless taskmasters would punish them for "complaining." When the king of Egypt died, the entire country was in mourning, and the Israelites exploited this opportunity to cry, since at that point, crying was socially acceptable as a sign of mourning the death of the king.
There is a Yiddish idiom: "to look for a badekens." A badekens is that part of the marriage ceremony where the parents cover the bride's face with a veil and give her their blessing. A highly emotional moment, it generally brings all present to cry. Therefore, if people are reluctant to cry for fear of revealing their emotional pain, they will "look for a badekens"; i.e. find an opportunity where crying is the norm, so that their crying will not indicate any personal pain.
Why should we need any subterfuge? What is wrong with showing our emotions? Why is crying equated with character weakness? Why should brave people not cry when they feel hurt? Where is the benefit in being an unemotional stone? We may read an account of a person who "cried unashamedly." Why should there be any shame in crying?
Our ancestors in Egypt suppressed their emotions because they feared their oppressors' retaliation. Whom do we fear when we suppress our emotions? Perhaps only our friends and peers, who are also suppressing their emotions because they fear what we will think of them. How foolish!