You’re more comfortable with your inner world than the outer one. Sometimes, you need to crawl inside your shell – just like a crab. You need to process what’s been going on in your life and to feel comfortable and protected. And this usually means staying at home and getting comfy with some of your favorite books.
But your friends and family understand that you just need some time. If you retreat to your private and comfy nest after a really hard day, they just don’t bother you. If a Gemini native did the same, their friends and family would be alarmed because Gemini natives are renewed by social contact.