I remember being a teen thinking about my views, and coming to the realization that I might be an "anarchist" (because I valued freedom and I couldn't find any area in life where govt action could be objectively good).
I immediately shunted that thought. "No, I'm not an anarchist. That's just absurd." No further rational thought, just an immediate recoil from a term I had only heard in a negative context from the very people I disagreed with on most issues I ever actually considered.
How far ahead I could have been if I didn't waste the next ten years trying to find a space in the fringes of the political system (voting for Nader, Badnarik, generally engaging problems as a central planner trying to fix things with a single grand solution). I should have just used this new tool (at the time) of the internet to find the Austrian Economists, Ron Paul, and the actual history of stateless philosophies rather than run in fear from a socially stigmatized label.
Ultimately, I don't have any specific issues I've regretted taking a stance on. Because I don't jump into positions.
I remember when I was first working and there was talk of a minimum wage increase. I didn't immediately say "Well, that's good" or "Well, that's bad." I remember saying to myself "What are the implications of a minimum wage increase, does it really do what they claim, and is it really worth it?" So I did my own thought experiments, I did my own math, and I did my own research.