One of the tricks is to have what you're doing - or what you're going to do - really small. This way you don't have enough time to become bored. For this approach to work, you need to be able to split meaningful projects into still somewhat meaningful, fun enough but small subprojects.

Another thing is that for many projects you're starting it understanding that you won't finish it - in one piece of time. You're going to start, progress, reflect on it, do some more - then put it on the shelf for a while. And this is ok. This allows you to actually boldly start projects which you know you won't finish - again, in one chunk. For example, I also took several courses on Coursera etc. and dropped then after a couple of weeks. But they are still high in my priorities - as soon as I can/want/return to the same subject of interest, I come back to the courses, reading the material, watching videos and even doing homework. This at least allows me, when taking that course second time (if I need to - usually I don't, the primary reason is knowledge, not the certificate) to feel right at home.

I'd say, don't throw away that list of ideas you developed while working on something - but check it, choose perhaps something out of it for the new list, may be you're still interested in some projects mentioned there.

And... you still have to be persistent at times. Don't worry - it's a source of great feeling when you actually finish something non-trivial - and only you know how hard it was, and you really learned things from that - and you know you're better because of that.

I'm not very good at finishing projects, but I've gotten much better at finishing books. Here's what I do: I keep a spreadsheet with all of the books I've read. I record the number of pages per book and I calculate for the year how many pages I read a day on average. I only allow myself to add a book to the list if I finish it. This has definitely given me an incentive to finish books.

Well, I used a similar approach when I was reading SICP. I decided that I would try to do two problems a day and I got really far (end of 3rd chapter) but at that time I felt I wasn't understanding things entirely. I also noticed that I had developed a tendency to search for a solution of the problem before even attempting to solve it (this was in case of hard problems). So, I stopped reading SICP because it such an amazing book and I didn't want to ruin the experience of it by ploughing through.

Structured procrastination tends to work very well for me. Whenever I have several things I want to do, I choose one as the Most Important Thing that absolutely must be done. This ensures that I'll finish everything else, while leaving the Most Important Thing incomplete.

Because information is so much easily accessible in our days, many people are facing your problem. The only way to finish something is to stick with it. That means saying No to other things that might distract you in the meantime.

Good luck and have fun!

1. While you have an active project, write down each potential project/course on a piece of paper.

2. When you finish a project, you can pick a new one. Pick the one you most want to do from the list. Throw away the list and get a new piece of paper.

3. Go to 1.

Have the same problem as you. I tend to just force myself to stay away from new opportunities and first finish what I am doing. Sadly this doesn't work so well for side-projects.

I simply dont give myself a hard time about unfinished projects/books/anything. Sometimes I just cant do it. Move on.