I've been asking myself this question over the past couple years ever since I left college. You might think it's a strange question to ask oneself, perhaps indicative of a low self-esteem, but it's actually about something completely different.
One of the hallmarks of my college experience, especially that of my freshman year, was the intense, personal, and constant exchange of ideas. Every night was a forum for a new topic about which my dormmates and I would debate, sometimes calmly and deliberately, other times passionately and sensationally, late into the night.
At the time, it was genuinely fun and invigorating. After spending our childhoods cooped up in our homes with parents telling us to do our homework, we could finally open the floodgates and indulge in our curiosity in different ideas and the desire to impress our own views upon others. In retrospect, our nightly debates were excellent practice. The constant push to think thoroughly about difficult topics, to form and express opinions, made me smarter, quicker on my feet, and overall, a more interesting person to talk to. It ties hand in hand with my theory on the source of intelligence. Intelligent people aren't necessarily endowed with more raw brain power (though many are); they've just spent a lot of time thinking about many things so that when a seemingly random topic arises, they have the associated knowledge and/or opinions already at their disposal.
Recently, however, I've noticed that my verbal agility is lacking, my mind wanders about shallow thoughts, and I generally don't have much to say when it comes to anything. It's not that I don't have an opinion -- I just don't care to express or fight for it. In other words, I've become boring.
Additionally, and perhaps most detrimentally, I've found my closest friends' company increasingly abrasive. Of course, everyone knows I love them dearly so this is nothing more than minor annoyance. At the root of the problem is that we all went to Stanford and therefore share the trait of being strongwilled and competitive, competitive not necessarily with each other, but with ourselves. In other words, we're never really good enough and feel compelled to be the best. Put simply, we take some things too seriously, from Halo to poker to Taboo to discussions about politics.
At first, I wasn't sure why this was annoying me so much. After all, I am just as guilty as they are of taking things too seriously. Plus, this behavior never really bothered me before; why was it grating against my nerves now? On top of it all, I feel an overwhelming drive to be absolutely passive and relaxed, to be boring.
After much thought, I came to a reasonable conclusion. I think I'm just growing up. This is not to say my previous behavior was immature, but it was just a different stage in my life. Now all of that competitive energy and analytical drive has been diverted to my job and my career. I spend all day at work exercising those very muscles and by the time I get home, I'm exhausted. All I want is a beer and some passive entertainment, and when all I find is more of the same aggressiveness, I become excessively turned off by it. Basically, my sense of work and sanctuary has polarized into well defined compartments and any spill-over simply irritates me.
The change is probably not as dramatic as I've laid out here; I think being burned out at work has simply exacerbated it. However, I'm glad that it's been blown out of proportion so that I have a chance to recognize and adjust to this newer tweak to my personality.