II. The laughter of a fool, Ecclesiastes 7:6;
The heart of the wise [learns when it] is in the house of mourning, But the heart of fools is [senseless] in the house of pleasure. It is better to listen to the rebuke of the wise man and pursue wisdom Than for one to listen to the song of fools and pursue stupidity. For like the crackling of [burning] thorn bushes under a pot, So is the laughter of the fool; And this too is vanity (futility).
Ecclesiastes 7:4-6 AMP
Even in laughter, the heart may ache, and rejoicing may end in grief.
Proverbs 14:13 NIV