Not seeing medical professionals as soon as medical problems arose. I now live with (likely) permanent chronic pain which may well have been preventable were the causes addressed at an earlier date.
The mental model that states that since all past problems have been inconsequential, all future problems must therefore be inconsequential is a problem here. Holding that mental state (my past problems have evaporated without issue, therefore my future problems will do likewise) is problematic because most people have not experienced enough major problems to draw on a meaningful sample size here.
Others have critiqued this idea on the basis that it's essentially lobbying by one interest group or another - even if you don't offer money for a campaign you can offer the votes of those people who strongly share your interests.
I'd critique it on the grounds that the triad of intelligent/politically unaffiliated/cares a great deal about this particular issue simply doesn't give you enough people to work with. Picking up people who are politically unaffiliated and have a particular passion about a political issue is much more difficult than it might seem. Most people vote on either self-interest or sacred values (or some combination of the two). Opposing homeopathy is probably a good idea, but you'd be hard-pressed to find people who can clearly see it's in their self-interest (a few million saved every year on needless treatments amounts to mere cents for them a year, most likely) or aligns with their sacred values (most people see homeopathy as stupid, not as evil).
I don't think looking into the theory of interests groups is a bad idea at all, merely that this particular technique requires issues that have significant political muscle to begin with. As a general rule I suspect good policy is better served by moving the Overton Window than by hacking various features of democracy.