I know in my own mind, and pretty sure in most peoples mind as well, I have a clocks that is ticking toward different events.  Once the event occurs it is usually subpar to the anticipation of said event so it makes me wonder as to why.  It also seems like If I don't have any reachable events on the horizon, I feel like I am stuck in a lull.  For instance, an event can be graduation or maybe a promotion.... pretty much any type of carrot that you have been working for or eagerly anticpating.  I guess this is they brains way of staying motivated or working toward a goal of somesort.  It could also be that I am a goal oriented person and most of you have no idea what I am talking about.  None the less it is an interesting study trying to dissect why I seem to need this in my life to stave away stagnation of motivation and thinking.  We often get caught in a rut with work and it may be that we have no real goal in our profession other than getting to the next payday.... or in todays climate.... keeping a job.  Food for thought.