Nolan has started using this "I don't know how" technique when he doesn't want to do something. Here are some of our conversations:

Mommy: "Nolan, come up stairs, dinner is ready"
Nolan: " I don't remember how to climb up the stairs"

Mommmy: "Nolan, you need to pick up your hockey guys, so mommy doesn't step on them"
Nolan: "I don't remember how to pick them up"

Mommy: "Nolan, put your milk in the fridge if you are done with it"
Nolan: "I don't remember how to pick up my milk cup"

Mommy: "Nolan, time to go potty before your nap"
Nolan: As he falls to the floor "I don't remember how to walk"


I hope this phase is a short lived one.