Boredom is virtually unknown to me, in fact I struggle to understand what it feels like. I sometimes experience what I assume is almost the converse problem though, an over-abundance of external stimuli. These usually take the form of events and impingements I am obliged to deal with, or more hopefully avoid, but have little interest in.
Most of the things I am interested in are very dependable ecstasies, music for example; always there, always ready to fill any lacuna in consciousness. Simple tiredness, strangely enough, can be caused by too little activity, mental and physical, as well as too much.