Perhaps you've already encountered the unlovely neologism "hangry." If you haven't, it's an unfortunate portmanteau of "hungry" and "angry," and it describes the irritability that naturally accompanies low blood sugar and elevated cortisol. Even if you've never heard the term before, you've almost certainly experienced the phenomenon. We've all skipped breakfast once or twice for one reason or another, and we've all delayed lunch. We've all felt the comforting tide of digestion ebb to expose the craggy rocks underneath, and even if we're scrupulously diligent about minding our food intake, we all know someone less cautious.
My crabby mood can ruin your good day. If my crabby mood is the direct result of skipping my morning bagel (cream cheese and lox are the only proper toppings for a bagel; anyone who utters otherwise shall be branded a heretic and shunned) then there's an uncompensated externality there. My failure to exchange makes you worse off. You should be willing to subsidize my breakfast, right?
No? You don't owe me breakfast you say? You don't want to reward my inattentiveness you say? You don't want to encourage future episodes of reckless fasting you say? You don't want me to take advantage of you you say? I see. Even though my mood has certain public goods aspects to it, namely that it is not excludable (and indeed, non-rival to some extent). it's still pretty widely recognized that my mood is my own responsibility.
Of course, when I say "widely recognized" I mean in the culture in which I live. It's a social convention. Contrast forager cultures in which the entire day's haul is shared proportionally among the entire group. And like other social conventions, they are subject to change. Terms and conditions apply and all that.
So it goes, it seems, with education. Education, like nutrition, is largely a private good: through my education, I earn higher wages, enjoy greater productivity, and so forth. There are many happy outcomes of education for which I am well-compensated. However, I am not well-compensated for my refined mannerisms (don't laugh), my keen ability to vote responsibly (okay, that one you can laugh at), nor my new-found propensity to conform to those social conventions that are coeval with an advanced university education. My college education unintentionally benefits you the same as my Moons Over My Hammy™.
As a fraction of total expenditures, higher education is subsidized (chiefly through non-dischargeable-in-bankruptcy lending) far more than food (SNAP, food banks & al). Unfortunately, just like me being a crankypants hold-out, subsidized students have less incentive to behave prudently in higher education.
So the Andrea's Question puzzle: we want students to be prudent in their decisions to seek education. Shuttering Sallie Mae is a political non-starter, and I struggle to imagine how to overcome what seems like an impossible pro-college bias among high school guidance counselors. I have faith in the power of rhetoric, and I give all the applause I have in my frail mortal form to Mike Rowe for doing his best, but I worry that attempting to raise the relative status of skilled physical labor is up against some extreme institutional barriers. What do you suppose the most effective prudence-enhancing approach still in the choice set might be? Suggestions welcome in the comments, because I confess myself with very few ideas of my own here.