This is exactly right, for me at least.
Sometimes its easy to know what is required, and probably guess at how long it will take (15mins or 1 day), usually because you've seen other people do it this quick. But if you don't know how to do it, and even worse, don't know where to start to learn it (which book to read, which course to take, who to ask) you can end up sitting about doing nothing but getting frustrated.
A great example is Linux. You know a task is easy (like creating an automated backup), but you can't just go and do it. You need to read up on it, you need to learn CRON and how it works, you've then got to read up on the subtle differences of your linux distro vs the one in the tutorial. You then need to read up on chmod or sudo to change the permissions, etc., etc.
Point is, it's an easy task once you know how, but when you don't know how, all you see is a huge mountain of learning you have to do to achieve it. And to make matters worse, sometimes the juice isn't worth the squeeze. Why spend all day reading up on Linux just to copy some files?
End result... I'll do it tomorrow