I searched through all my fabric for just the right color to make the sashing for my quilt and finally found just the right one. Got my tape measure, pencil and paper and figured out how many pieces, size, etc. and of course the piece of fabric was too small. Got in the car and drove to the fabric store. Luckily, they still had two yards of it. They also had several other pieces of fabric that I couldn't leave the store without buying and breaking my self imposed rule of no more new fabric.
Got home washed the fabric, ironed it, got ready to cut it and realized that I had miscounted the sashing length and I did have enough fabric in the first piece and really did not need to go to the fabric store at all.
I cut all my sashing and I measure it again and I've cut it too short so now I do need the new fabric I just bought but I decide I better take a break.
Two hours later and feeling a little better I go back to the sewing room and look at the pieces again and realize they are the right size after all.
Sometimes I wonder why I do this ;-)