My Notebook and my Treacherous Brain

Do you carry a notebook? Something to jot down ideas in, even if it is just a name that pops to mind, or a simple phrase that arises in your head that you can imagine one of your characters saying. It certainly is one of the things that people are advised to do; have a notebook on you at all times.
I have a notebook. I bought it for myself as a little treat. It's a pocket moleskin book, with squared pages, just in case something needs to be sketched, rather than written. In the first two weeks, it never left my pocket. I would scratch down ideas, mispronunciations of words (in case I wanted to have a character to whom English was a second language), small ideas that popped into my head. Tiny observations of the oddest things.

Suddenly, it all dried up. I had gone for more than a month with nothing to add to the notebook. I put it down to my perception. My force of attention was obviously being directed elsewhere. I had other concerns (family issues and university tasks). I had not used the ideas I had already recorded. My brain wasn't on form, but it would probably come back.
After two months, I stopped carrying the notebook with me. I didn't see the point.
And the ideas started coming back!
This has perplexed me my entire life. How can I be so full of ideas when I have no way to record them, yet when I have a notebook, smartphone, sketchbook to hand, my brain falls silent?
A concept struck me that I think answers the question: My notebook had become a reminder of a responsibility. The more I attempt to write, the more I feel the duty of output. This made the notebook no longer a tool to aid in my collection of ideas, but a task master, demanding ideas to feed it. This has never been a good place for my brain to be.
How do I escape this panic? I have to listen to my own advice. The muse is not inspirational of itself. Inspiration comes from being the muse. I write something in the notebook every day, even if I end up scribbling it out the following day. That way, inspiration will come, if only intermittently. When I have one good idea, it sets me up for the next good idea. If I can connect enough good ideas together, then I have a story.