Do you have a folder with many many abandoned projects in it? I have over 200 in mine.
Some I've abandoned in a week, some even in a day.
I started feeling guilty about this and for a while decided not to start projects unless I felt somewhat committed to them.
But you know what? After looking back on this decision, it wasn't such a good one. I haven't started gotten many new projects underway recently, and this way of thinking might be to blame. Now instead of just doing some work, I end up just daydreaming "gee, that might be a nice project". Then I come up with reasons why it won't work and don't proceed.
Starting a project and hacking on some simple things is a perfectly valid way to think things through with it. Maybe there is a problem with it, but at least you'll learn more in the attempt. Starting and abandoning it after realizing the issues is fine. Disk space is cheap.
By actually writing some code or doing a basic site layout you can start thinking in practical terms, instead of living in fantasy land. Had I only bounced an idea around in my head, I would never have gotten to the point of finding the reasons to reject it. And sometimes, just sometimes it turns out that things click.
Only through actually doing some work on it do I force myself to REALLY think about the project.
Looking at it like this, it is actually completely natural to abandon most projects at super early stages. While most are abandoned, some survive.
I will return to my habit of a lot of little project directories. This time guilt-free.