A juggler requires strong concentration, focus, strength and dexterity, a good sense of balance to be able to perform well, keeping all those balls in the air all the time, so that at the end, he will receive applause. He cannot allow himself to be distracted, and needs to just focus on that one thing he is doing at that moment.
A SAHM is a juggler too. She also needs focus, balance and strength - the inner kind although the physical kind is required too - to carry loads of groceries, laundry, a sleeping child, heavy pots of plants in the garden, buckets of water.... But unlike a circus juggler who has just objects to juggle, a SAHM juggles responsibilities. Juggling responsibilities involves dealing with time, money, people, behaviours, emotions. So many variables to the responsibilities and so many variables to the variables. The right time, the wrong time, enough or not enough time, enough or not enough money, naughtiness, stubbornness, obedience, anger, frustration, patience, impatience, sadness, disappointment, excitement, happiness...you get what I mean by now.
For jugglers, be it five of the same balls or five totally different objects, they are just objects. If they make a mistake, they drop the balls and if the objects are breakable, they just fall to the ground and break. Then they can start over again. The broken objects can be thrown away and replaced with new ones.
For SAHMs, if they 'drop' the responsibilities, they sometimes cannot start over again. They often get distracted by the demands and needs of the various responsibilities and people and things around her. When they make mistakes, the time, the money, and people cannot be replaced. It's harder for SAHMs to focus, to find balance when juggling responsbilities. And the applause is seldom forthcoming too when they succeed. The rewards are never monetary (unless you make a pre-SAHM agreement that your 'employer' pays you a monthly salary!) and they certainly don't gain fame.