Any legit answer to this question would be contextual therefore not really practical for anyone. For example, I may say "I wish I hadn't learned to play video

Any legit answer to this question would be contextual therefore not really practical for anyone. For example, I may say "I wish I hadn't learned to play video games", but who knows I will go on to build a video game empire because I was so inspired by it? Or, I would turn into a video game junkie and live in my mom's basement till I die. The only difference in the two completely opposite outcome is how I dealt with the reality, and has nothing to do with the skill I learned. The only correct answer to "I wish I hadn't learned" is about timing. A lot of innovation in the world is achieved by people who's relatively a newcomer in the field because they have a fresh perspective. All the "experts" think the same way so they can't really come up with a true innovation. But even in this case it's more about timing and context, and there's no absolute answer to it. If someone thinks "I wish I hadn't learned X" NOT in the context of timing, I think it just means the person needs to see the world in more positive light and realize that they can change themselves at will and do whatever they want. A skill doesn't ruin you. You ruin yourself.