For me, it was learning English. Although I do make a few mistakes here and there, I’m mostly perfect on it.
The amount of resources you have access to dramatically increases when you know a universal language. I say dramatically because it made me realize how much my native language lacks when it comes to certain topics. The most obvious one to me was tech and computers. Everybody knows how to use Windows but there are very few resources about stuff beyond Windows. It’s actually sad. [insert sad face here]
Oh hell yes it is. I didn’t stay too long (I’m notorious for leaving anything I’m unhappy with) but it was only good for like the first couple of weeks. I honestly should have known better but I was 18.
And for all the folks saying that getting married is the best thing to happen to them, I only have one thing to say: good! I’m glad it’s working for you and your spouse!