Planning Versus Real Time Intuition

I have a question about actions planning to get goals done.
Here is an example : I plan 2 hours to work on an article at 3pm. At 3pm, I feel that I really want to work on my web site. I noticed that when I listen to that unplanned desire and change my plan, I end up working very efficiently (on the web site in this example), and in less time than what I would have imagined.
So I thought I would plan my work slots, without precising the tasks, and rely on my “intuition” of the moment to define tasks.
But then I watched the course about “how to get it done”, I found that planning in advance the exact tasks is also a very interesting approach.
Now my thought is : Maybe I’m losing the magic of the real time intuition by planning everything ahead of time.
I would like to know your opinion about that thought please.
Thank you !