In my case, talking about carelessness and thoughtlessness, everything depend on how you feel, which sort of emotions possess you. I'm quite emotional, and the stress is my enemy, which always makes me careless and thoughtless, it freezes my mind, though I draw all my attention to my work.
When I'positive, doesn't matter what is important or not, I've got a feeling that I'm the attention man that keeps everying under control!!!!
My verdict: live beeing positive, have a goal in life and you forget what carelessness and thoughtlessness is!!!