The biggest obstacle I've been running into while learning how to code is that I don't have someone that can sit there and go over my code and debug it for me. So any time I start taking lessons, there comes a point where I just can't figure out I did wrong, and I have to give up. I've gone back to the same lesson a hundred times and still can't figure out it.
That is my major hang-up, and a friend of mine who has been trying for years to learn on their own feels the same way. You need an actual person to tutor and help you through the rough spots or else you simply can't move on to the next lesson.