So here's my story:
I just dinged level 100 with my fire mage alt. Until then I was thinking it was "fine but lacking", The levelling was a bit slow, the gameplay a bit clunky.
THEN randomly I check the tooltip of Fireblast and I just discovered that I can freaking cast it WHILE CASTING FIREBALL. Until now I would just wait for the fireball to hit and check if it proc'd to cast it...
My life has changed since.
Gosh what a noob.