It's weird how things you do can be implicitly quantified in a misleading way. This is usually obvious in work productivity measures like Agile burndown charts and Jira tickets and the like, but it also happens outside of work.
Just now, I implemented unsubscribing in a mailing list manager I'm writing. I didn't implement it perfectly, but I did get five unit tests to pass. That took fifteen minutes, and it looks like "I really did something."
In the four days previous, for 2-4 hours a day, I worked on this line in the
Book of Shaders:
Make rows of moving cells (in opposite directions) with random values. Only display the cells with brighter values. Make the velocity of the rows fluctuate over time.
I worked on a variant in which the cells were defined by moving horizontal and vertical bars but still in the spirit of the exercise. Things weren't terribly complex but still complex enough for a space I wasn't familiar with that I had a lot of subtle (and few not subtle) bugs to work through. I did learn quite a bit by doing that, but from a "explain what you spent over eight hours on" point of view, you could see it as "I did one line in a tutorial."