Imagine you are happily knitting along and notice that you made a mistake in your work... 10 rows back. It's happened to all of us. Do you really want to rip out that many rows to correct the error? Of course not. That's why every knitter should know how to fix mistakes by working down a column of stitches. Yep. You unravel your stitches down a single column.
Before You Begin
This is one of those skills that seems really scary at first. You drop a stitch of your needle and it unravels down to your mistake. Then, you fix your mistake and, one by one, rework the stitches back up the column. After you give it a try, I think you'll agree that fixing those pesky errors down a column is no big deal.