I've had that feeling recently after I was underway on a new story and "BLAM" Wrong Summit! Not only was it the wrong summit, I think it was on a whole different mountain range somewhere in the Appalachians. Now I have to travel all the way back to the first step and start at the trail head once more.
Now I've got to find The Backbone Of The World again and get the lower end of my backbone booted and realigned. Finally getting reliable information was a big plus. I just wish I had done it earlier in the year. I guess you live and learn and bring better maps!