No swatch? No Success!

No matter what you want to knit, knitting a gauge swatch is NOT OPTIONAL!

Without knowing gauge:

How do you know how much yarn you need?
How are you going to know if the finished item will fit?
Determine if you are even going to LIKE the resulting fabric
Try out the chosen stitch pattern, maybe it's too tedious... learn this BEFORE starting to knit
Dress the swatch and check for shrinkage, pilling, fading
Save time by knowing AHEAD if the yarn will knit easily