Here’s a little advice to students picking electives.
Consider taking classes in those things that would be hardest to learn on your own after you graduate. Taking the most advanced courses available in your major may not be the best choice. Presumably you’ve learned how to learn more about your area of concentration. (If not, your education has failed you.) So the advanced courses might teach you the material you’re best prepared to learn on your own.
Maybe it would be better to take a foundational course in a related area than an advanced course in your main area. For example, I suggested to some statistics graduate students yesterday that they take a really good linear algebra class rather than taking all the statistics they can. If they become professional statisticians, they’ll continue to learn statistics (I hope!) but they may find it harder to take the time to really understand mathematical foundations.