Yarn reality frustrations

I have a lovely book (bought on clearance even!) for very simple but classy sweaters. I have lovely yarn, in great colors, waiting to be used on the right pattern. I blissed out for a few days, thinking that the combination of yarn and pattern would not only whittle down the stash, but would knit up quickly and look fabulous on me! Reality hit when I started a swatch.

Patterns always tell you to check your gauge. Knitters always tell you to check your gauge. My mother tells me to check my gauge. I've already posted about a sweater disaster that was the result of not doing what I'm told. But I just have grouse a bit about this...

The yarn and the pattern I've selected never seem to match. Never. I've fiddled with needle sizes, I've been careful to buy a yarn similar to the one suggested in the pattern, my stitches are neither too loose nor too tight. I think it's a plot to get me to buy more yarn than I already have stashed. If nothing else works, I'll go out and buy the exact yarn used in the pattern, right? Grr.

I'm sure someone with more experience could calmly explain that I am missing something important that just makes it all work out okay. Or maybe they can't and I just have bad gauge luck. After the brown disaster sweater, I'm not ready to hop into another large project without being absolutely sure of myself.

I'll try once more (with one more needle size) to work out this white mohair boatneck that i'd love to wear this summer. If I get too frustrated, I'll go back to felting. It's only a little unpredictable (I don't felt swatches, and different colors can shrink differently), and it hides a myriad of little oopses. Just my style.