I highly recommend both of them, if they cover a subject you're interested in, though if you only have time for one, they are listed in descending priority order.
Given how low it's time+energy requirements are, and how large the pay-off has been, I recommend Learning How to Learn by Dr. Barbara Oakley to everyone regardless.
A meaningful part of what I found useful was that I knew ~<10% of the content. It was 8 hours effort (Tuesday+Thursday 1 hour lunchtimes for four weeks, including all videos, quiz's, note taking (on the phone I was watching it on), and tests), and I'm now sure I know how to study effectively.
I think one working day is worth it to make sure you're up to date.
I also found the working memory, and memory information in general very informative and helpful.
How do you apply this? Let's say we want to learn a new programming language. I should spend time focus on a topic, then how do I apply diffused thinking here?
I learned to value physical activity for diffuse thinking, and related to it when I unconsciously feel the urge get up and walked around the room when thinking about some subjects I've learned.
What part of the course do you feel it's valuable? I don't mind going back to do it again.