On the contrary, your participation in any insurance program is optional, I force you to do nothing.
What is "smart" for your may not be "smart" for me. I shouldn't have the option to make you fund what is smart for me, especially when I have other options.
And yet the literature on public economics is clear that the long-term efficient outcome for any given individual, ex ante, is a pooling equilibrium in health insurance. An individual such as yourself may be a "low risk" insuree currently, but your long-term risk profile will differ from your evaluation of your risk today.
This is the challenge of many investments; people are unable to accurately assess their individual risk profile and do not take a Bayesian approach to pricing their risk as new information arrives over time.
A parallel argument exists for upside risks, such as investments in human capital. If we're rational, we ascribe population averages to individuals. However, after that point, we don't properly account for differences in information as those individuals approach the frontier of post-secondary credentialing.
On a side note, the U.S. military has a whole bunch of openings for employment with the side benefit of paying for your college tuition and teaching valuable leadership and discipline qualities. As a tax payer I'm already funding that option. If one isn't willing to invest in themselves, I fail to see where it's my responsibility to invest in them in their place.
This assumes that all individuals are eligible for military recruitment. Because of the correlation between low SES and poor health outcomes, over-reliance on military education as a funnel for access to post-secondary training may be inappropriate for the poor, and may disproportionately penalize the most physically or mentally vulnerable.
At 18 you're an adult, you become your responsibility at that age, responsible for your actions and responsible for your own well being. You stop being the responsibility of society. At this point, anything you receive from society is a gift and should be of free will.
And yet society is responsible for the effects of so-called adults' behaviour if it is costly to society, either through crime, unemployment, untreated mental illness, physical disability, or behaviours which perpetuate inter-generational poverty and abuse.
Education is a known lever which prevents those downside expenditures. Reliable quantitative techniques exist to calculate the break-even point where the trade-off between extra educational spending offsets the cost of additional social program spending due to its absence.
