Two steps forward, one step back

I have finished the back of the vest. I thought I was ready to start the armhole shaping on the front last night, but discovered, in my last self-satisfied look at my progress before going to bed, that I had skipped 2 rows of garter stitch a couple of inches back, so will have to retrace my steps and fix it. Still, I'm within sight of the end. I just hope I like the fit. The combination of cotton yarn and a somewhat stretchy pattern make it hard to judge exactly what the final blocked and assembled measurements will be, let alone how well I will like the effect on me.