I, like many, alter almost every pattern I come across. I think it is ridiculous to knit garments flat; if I wanted a sweater with seams I would go to the store and buy one. One of the greater glories of knitting is that it is easier to get a seamless garment than it is to get one with excess bulkiness at the sides. I also generally slip the first stitch of every row if I am knitting something flat, a scarf or swatch for example. I generally alter patterns left and right and feel very smug and clever.
This doesn't always last very long. A lot of times I alter a pattern before I even think about it, then after all that excess work and thinking how dumb the designer was to do it this way I realize that I am in fact the idiot here. Luckily this is only knitting and not world peace-keeping, it does have a tendency to bring me back down to earth with all the other knitters however.
Currently I am knitting Woolly Pears by Nicky Epstein from the Interweave Knits Holiday Gifts magazine. Since the project was small I decided to try it first without alteration and see where that got me. I couldn't help slipping the first stitch of every row though, I just like how good it looks. I finished and was quite pleased with the results. Including my terrible seaming skills. Then I tried another one exactly as written and it turned out even better. I guess I am not as much as a genius as, say, someone who has written several successful books. Everyone has their day.