Answer:
They don't forget.
They can swim but theyโre not fish, they are slow but they are not turtles, they live and hang from tree but theyโre not monkeys. What are they?
What jumps when it walks & sits when it stand?
In the fields a frightful thing. Watch it and you will find, it has a pitchfork in the front, and a broom back behind.
It has plenty of backbone but doesn't have a let. It peels like an orange but it comes from an egg.
I build up castles. I tear down mountains. I make some men blind. I help others to see.