Because mumma is involved in too many different kinds of work, possibly also missing out on her sleep as well in trying to make her child sleep first. Mummas sleep last and wake up first because of the care they take for everyone. But who will take care of them? Hence their tiredness piles up.
Also children are growing up so nature has provided them with mechanisms to supply them energy from all around. This is not the case once we grow up. We have to then keep a conscious balance between receiving and spending energy.
Affectionately,
Alok Da
