As a variation on this, I've discovered over the years that "resistance" to working on a task sometimes comes from a clash between a conscious thought that the task should be easy and an unconscious realization that it's actually not going to be easy at all.

It's sort of the internal version of having a manager present you with a task and telling you up front that it will be "easy". That's enough to elicit a silent, knowing groan from most of us.

The good news is that often once I accept that a task is really quite complex and will take a long time, the resistance fades, and it becomes easier to start working on.