When you spend your time alone (or work at home), you have no reflections, no mirror or validation from others.
We may not even realize how important it is to your equilibrium to have people - and successful dealings with them - to let you know you are alive. And functioning.
A trip to the grocery can stretch out as you smile at and make comments to other shoppers. You may even find yourself asking the workers the locations of things you don't really need.
When your spouse gets home from work, you can't wait to spew the thousands of saved up words. To see the expressions of awe or gratitude, agreement or doubt; emotions to reflect your own feelings and experiences.
I love my time in the quiet house to write, to do my computer work, to contemplate. Yet sometimes, I feel like the child who calls out in the dark and gets no answer.