Cheers Jeff, good luck to you as well!
I feel you on the “boring and pointless” comment, I felt some of that when I went through the algorithms MOOC as well. Having a teacher and classmates made all the difference in getting through that barrier; they provide motivation and make the content engaging, and assuming some minimum level of initial interest, it’s a much more enjoyable experience with them.
You’re correct that arrays are more generally useful in day-to-day programming, but if you’re always trying to improve and solve bigger, more important problems, I bet one day you’ll come across a situation where the constant-time insertions and deletions of a linked list come in handy :)
I’ve been studying machine learning recently too, and enjoying it! I went through course.fast.ai and they have fewer problems but they go through complete solutions to each of them in detail. It’s the highest quality “up to date” material I’ve found. Let me know what you think!