Do you know anything about complex numbers? This is where all that complex number rubbish you learned comes in.
A capacitor has an impedance of 1/jwC (where w is 2*pi*f). An inductor has an impedance of jwL.
If you multiply numerator and denominator (and Governator?) of 1/jwC by jwC, you get jwC/(-w^2C^2) = -j/wC - a negative imaginary impedance.
Naturally jwL is a positive imaginary impedance.
Drawing this on an Argand diagram, your resistance will span along the x axis (it has no +j or -j component = no imaginary impedance), your inductor impedance will span UP the y axis and your capacitive reactance will span DOWN (negatively) along the y axis.
This represents real and imaginary impedances pictorally which is much easier to look at. In the real world, if your imaginary power is too inductive (if you run a printing press with lots of inductive motors), you can add capacitors across the rail to cancel the +j component with some -j component. This is called power factor correction.
See - this stuff they teach you at school does have some real world applications.
Sorry for the lecture, but I feel better now
Let me know if you need it explaining more (or waking up)