Mistakes in Work

I'm working on a baby blanket and realized I had made a mistake 3 rows back.  So I had to RIP back 3 full rows to correct it.  I can't say I like doing that, but after I correct it I feel a since of accomplishment.  The first thing I ever made was a granny square afghan.  I made and remade those squares in order to make them all the same size,  I had a problem with tension at first.  By the time I finished the afghan the yarn looked worn, lol.  However I was very pleased with my first project.   I must admit on some of my more delicate work, such as doilies,  I haven't noticed the mistake until I was finished.  I just leave it if it isn't noticable and consider the piece unique, lol.  Most people who don't do needle work will never see the mistake.  Since the item is a gift they always appreciate it regardless of a slight imperfection.