親の心子知らず (おやのこころこしらず): children do not know how dear they are to their parents (and therefore act selfishly)

children do not know how dear they are to their parents (and therefore act selfishly)

Children do not know what their parents feel for them. Said by a parent with a sigh, and by a grown child who has just understood it far too late.

A Japanese proverb (ことわざ)