I get wanting to read a book instead, that's what I think about packing social life on top of hard work/commute schedules, like where do you get time to do stuff YOU personally want to, like read and stuff? I don't know if it's extroversion or introversion (though I've never been called an extrovert in my life) but it is sometimes about keeping a certain level of mental contentment versus slipping toward feeling very discontented with/in the moment. Too much loneliness takes a mental toll but so does too much socializing. Sometimes maintaining this mental balance even needs a feeling of purpose and accomplishing something, like reading a book feels purposeful. So does walking.