More care needed

It was all going so well - I started knitting "Sonnet" from Knitty's archives last Friday and yesterday I finished knitting the body. Yippee! I thought, I'll get the sleeves finished over the weekend and I'll be able to wear it on Monday to the final ExTex of the year. Last Monday I wore my silk top, which I had been knitting during class the previous week; this had led to some of my fellow ExTexers making comments about my supernatural speed, so I thought it would be funny to wear another new knit and see how long it would be before someone suggested sitting me on a ducking stool!
Alas, my plan has been thwarted by nothing more than my own impatience. I had worked out that my tension was 3.5 stitches to the inch and knitted accordingly. When I tried on the finished body, it was too long and too tight, so I measured again and discovered that I was actually getting 3 stitches to the inch and some sections that should have been 4" wide were only 3.5". My original swatch was a bit rushed (yes, I'm big enough and ugly enough to admit my mistakes) and in my hurry to finish I had been s-t-r-e-t-c-h-i-n-g- when measuring. Will I never learn?! Slapdash, or what?
Anyway, the net result has been a lot of frogging, even more cursing and a great deal of self-admonition.
Progress on "Sonnet" so far - about 1.5"!!!!
Despite all of the above, I am totally in love with the "Monet" colourway, so every cloud and all that!