When I'm feeling unhappy, I like to blame others. This gratifies my ego, but it also makes me even less happy. There are always changes I can make to be happier, including:
People often ask me to do things, and I often say "yes." Then I enter a mode where I try to cram too many things into my life. The solution is simple: I choose what I want to do with the time that I have. If I want to do something, I can make time for it. If not, it either doesn't matter, or I need to rearrange my priorities (the former is much more common than the latter).
Shallow friendships bring me slight joy. I derive more joy from a few deep friendships than from all the shallow ones combined. So I want to focus my time and resources on my deep friendships.
I took a course covering several programming languages from David Wingate.  Each language teaches me unique ways of thinking about problems and solving them. By knowing more languages, I can draw useful concepts from all of them when I write programs. The end result is more elegant software, and more fun.
I took Steve Petersen's Environmental Biology course.  As a fairly average American, I use a lot of resources, including water, electricity, gasoline, natural gas, jet fuel, plastics, paper, etc. One heuristic that I use to reduce resource consumption is to spend less money. My rationale is this: generally, the more expensive something is, the more resources were used to produce it. Perhaps it is also better to spend money on things like movies and music that consume human resources rather than physical resources. I can give the extra money to those who desperately need resources.
It took a course in Bitcoin. Cryptographically, the design is very impressive. It was intellectually enlightening to learn about Bitcoin. However, Bitcoin is not a good currency because the flow of Bitcoin is easy to track and the Bitcoin network cannot process very many transactions per second. 
In 2020, I worked with multiple tyrants. A tyrant is someone who uses his/her position of authority to impose decisions on others. In a democracy, the members of a community make decisions together. I prefer to be part of a democratic community because there is more personal freedom, which leads to self-reliance and better overall outcomes. In the words of Adler, "listen to the voice of a larger community." All conflicts are like "a storm in a teacup" once you step out of that troubled community and into a larger one.
This year I read The Book of Mormon.  I believe that it contains God's word delivered through ancient prophets. I generally read it multiple times per year, but this year I read it only once. By reading slowly and pondering, I feel peace.
 David Wingate
 Steve Petersen is one of the happiest people I have met. It might be correlated with spending a lot of time outside.
 Bitcoin can process between 3.3 and 7 transactions per second. By comparison, Visa can process a maximum of about 56,000 transactions per second, and it processes an average of about 2,000 transactions per second. (On Scaling Decentralized Blockchains, Croman et al.)