Maybe you’re looking for, “Ignorance is bliss.” 
Nah, too much interest in the world around you indicates that your own little world is too dull to keep your attention, and therefore you must be less intelligent
Threads like this are such a laugh.
Whenever the topic of intelligence comes up on this message board, as night follows day there will be a whole troop of Dopers trotting out self-deprecating references to their own brilliance.
Just let me sit back here and bask in the glow of your collective genius. 
Well, it seems to be the unpopular opinion to agree, but agree I must. I suffer the same situation. It is virtually impossible to engage in a stimulating debate of just about any issue in such a relationship. That breeds contempt. If all I wanted to discuss was auto mechanics and the sports page then I’d be fine, but I would once in awhile enjoy a challenging banter on current events, world news, etc., but that ain’t happening here.
I feel for you and your lack of intelligent conversation.
Why would you be with someone whose intellect you feel contempt for? That strikes me as *your * failing, not your partner’s.
If you’re so confident of your mental acuity, why don’t you find someone to challenge it, instead of bemoaning the fact that you’ve settled for a simpleton?
Smart people don’t sit around saying “I’m so smart, nobody understands me.” Smart people find ways of making themselves understood.
I heard some Steely Dan lyrics this morning that made me think of this thread:
“You been tellin’ me you’re a genius
Since you were seventeen
In all the time I’ve known you
I still don’t know what you mean”
Well said–and it’s not just the not sharing of intellectual curiousity–it’s the amazement/disgust/incomprehension that you would want to delve more deeply that gets me. To tell me that discussing X is a waste of time is to dismiss me, in a certain sense.
To the OP:
People grow and change as they age (we hope)–you may be outgrowing your wife (although the examples do not really support the point I think you were trying to make).
You have a number of options: put up and shut up (which seems to be popular in this thread), find an activity that you both can share that feeds your need for dialogue, get an outside intellectual interest that absorbs you–you will meet other like minded people which will help, ban her from your life. And any number in between the two extremes.
Wow.
<rolls the word ‘arrogance’ around on his tongue>
Hmmm. Doesn’t seem unfamiliar.
Seriously, folks, my poor attempt at explaining my state of mind in the opening post was indeed pitiful. For everything I listed as a problem above, there are a hundred things that are great. And my list was disjointed, at that. I also called myself taking pains to show that what was wrong was me and my attitude, but it seems, from the responses, that I didn’t do such a good job there, either.
My initial reaction was to feel defensive, admittedly, but then I began thinking about what I’d said and what you all had to say. Lots of food for thought.
I have to say I was surprised by the vitriol from some of you, but again that has to be my fault. If you weren’t aware of the complete picture, who’s to blame? If you read things that I feel were just not there, then that’s the nature of the beast when communicating in a text medium like this one.
Thanks for the responses from one and all, whether good or bad. All of them were thought-provoking. And a special thanks to those of you who answered my question.
HEY! That’s…nah. How about “Stupidity is sublime”?
And when caught or called on it I will say (if I can get away with it):
“It’s the only way I can have an intelligent conversation around here!”
I’m pretty stupid, and it’s no better being like this.
Trust me.