The importance of Gauge

OK, I'm officially converted to a swatch knitter. Remember my 4th of July FROG decision? Well, I finally re-wound the alpaca this morning and was ready to start the Better Sweater again. . . hoping it actually would be better this time. So, I decided, I'd knit a swatch. . . 6sts x11 rows should be 4 inches. It only takes me a few minutes to knit this up. . . and what do I have? 6sts x 11 rows = 2in x 4in. NO WONDER THE SLEEVE DIDN'T FIT!! I just took the yarn store's word that the Plymouth Baby Alpaca Grande was the same thickness as the suggested Cascade Magnum. Clearly, the Magnum is MUCH bulkier! So, I'm starting over, doubling the stitches. . . haven't quite decided how to increase by 2 at the raglan sleeve each row, but I'll do something. And now I'm excited. . . so I must knit. . . only have 2 hours before we have to leave for Rock & Roy!