[Gogar]

I learned that if you want to run some 14/3 or 12/3 and use the two hots to feed a 120 circuit you can share the neutral but you have to use a dual breaker that will trip both circuits, and sharing the neutral might make your GFCIs not work so you might need to just use a GFCI breaker instead.

But I learned it 'before', not 'after', so i'm happy.