I'd like substantiation for this because it simply is not as much of a rule as you state.
You've just engaged in an elemental bias while stating such things are "nonsense".
While you will be able to find some studies that suggest a correlation between education and left wing I've always veered more to Hans Eyxenck, who posited that Learning and intelligence can predispose one to centrist views, and avoidance of extreme political views. Indeed, and jmo, Eysenck would be a good refresher for a lot of todays young practitioners of militant extremism. But they probably wouldn't like reading it or heeding it.
Historically speaking there is correlation between age and shift from Left to right that is well established in the literature. Its just as clear, or more, then any relationship between University Education and being status quo left.
Do we really become more conservative with age? | James Tilley
As somebody that was "idealistic" once, and there's a fair amount of us my age, and my education, similarly predisposed, the shift to right is notable, very notable. For some of the reasons already expressed in the thread, and regardless of education obtained.
Notwithstanding individuals that work their whole lives in ivory towers or academia. But most of us in life shift from idealistic to pragmatic principles, and with our mores and values still intact.
Personally, I tend to be fluid on the spectrum. Not fixated on one brand democracy. I'll vote for the better candidate, party, platform, at the time I assess them to be better.