“When am I ever going to use this?”

I can’t imagine a phrase more commonly heard by teachers who educate students about calculus, differential equations and other advanced mathematics. Of course mathematics has solved significant problems in finance, engineering, business, science, and any other industry, but mostly in math class the focus in on fundamentals rather than applications.
This is purposeful. While good teaching should entertain to create interest, it’s up to the individual to find and develop applications of the knowledge. The necessity for math won’t be known until a problem is uncovered that doesn’t have current solutions. Pioneering something new isn’t as likely without it.
Many people can apply a simple equation, few can develop new methods, understanding or principles.
Those who do are leaders.
[Think about this for 5 minutes.]
The answer to “When am I ever going to use this?” is “When you stop following and start leading.”