I do this and I get stir crazy usually after I go through something emotionally challenging/draining, ect. It can last for quite a while until I rediscover myself and feel content just sitting down and enjoying my own company. Idle time and an idle mind can bring about emotions that sometimes people are not ready to face. It is almost like an escape of some sorts that you may be trying to deal with for the time being. Even taking up new hobbies and new interests can be a form of escape. It's not a bad thing. It helps you get through tough times, but at some point you will have to settle down and allow that idle time to kick in. Maybe you'll be more prepared when it happens. That's just my take on the situation though.