>surgery theory
doesnt help in the operating room
>intersection theory
completely useless for managing traffic
>analysis
will never help with anal
>toplogy
no help in drawing maps
>model theory
not used in looksmaxxing
>field theory
no help in farming
>lie theory
will not help you learn to lie
>harmonic analysis
will not teach you harmonica
>game theory
will not help your aim

I could go on, but the point is math is USELESS