My life would be so incredibly difficult if my wife didn't stay at home. When I come home our 20-month old is ready to play and I just don't see how she does it

My life would be so incredibly difficult if my wife didn't stay at home. When I come home our 20-month old is ready to play and I just don't see how she does it all day, keeping up with a never stopping, never slowing, ball of energy.