Practice makes perfect - Multiboxing "retrains" the brain.

[Multibocks]

I would argue that practicing multiboxing makes you better at multiboxing.

You're basically configuring your alts for remote control, not remote operation (meaning, all your toons are at the same place at the same time).

If you were playing one toon in Molten Core and another in Black Wing Layer at the time, thats multitasking. Multiboxing is somewhere inbetween.

This is what its like to heal and dps in a raid. Too much going on! Something's gotta give....