Answer:
This is a tough one, but I have to say, be fluent in every language.
Step-by-step explanation:
I was tempted to go for the instrument one, but thinking about it, being fluent in every language would come with so many benefits. Let's say you've always had the strong desire to move out of your hometown and move far away from there. Depending on where, there might be a totally new language you're not familiar with. If you were fluent in every language that exists, this wouldn't be an issue. It just saves a bunch of time for you. (Bonus example: Imagine you went to the grocery store and you had people around you sh#t talking you in a different language. Ohh the look on their face when they realize you understood everything they said is so powerful haha!)
BTW thanks op for the question. I was in need of some points.