When someone excludes themselves from society and attempts to improve on a certain factor of themselves such as a particular skill, their personal appearance or an assignment so when they're done they feel like a beautiful butterfly.
Person A: "Is Andrew coming to the party?"
Person B: "Nah he's cocooning."
Person A: "What for?"
Person B: "He's trying toget in shape."
Derived from the word cocooning, this word more accurately describes the act of retreating from the world and insulating yourself for a period of time due to feelings of being overwhelmed, crazy or unstable. It is most effectively used to reassure your friends that although your behavior might seem troubling or anti-social, you are still sane enough to have a sense of humor about it and will not be rocking in the fetal position.
"I've had a really crazy week so I think I'm just going to be coocooning this weekend."