Exactly how I learned to touch type; only it was Discord not IRC. The more things change, the more they remain the same.
MSN messenger in my case haha
Because I was rapidly going back and forth between the keyboard and mouse, it resulted in an unusual style where I use the outline of the keyboard for hand placement, and attempting to use the home row slows me down significantly.
Tribes in particular also had a voice-tree, and while it was shorter than prose it still encouraged a certain degree of touch-typing.
For example, typing VSAF (mnemonically [start][self][attack][flag]) led to text and prerecorded audio for "I will attack the enemy flag." Little of it survives now beyond references like VGZ for "Shazbot!"