I pretty much learned Go by doing in a way similar to what you have described here. After a long career writing Java I was introduced to Go and thought, this is a breath of fresh air. I used to think Java was well and deliberately designed and engineered. But after 20+ years the shine is definitely gone and Go now takes first place for me in my work.
Go is so much more concise and can do so much without the huge expense of all the frameworks like Java’s Spring and whatever else has to be dragged into the JVM and Application Servers to make an application work.
I have written it before, but once I tried Go, I never looked back at Java again. I predict, Java will eventually fall to the wayside and be replaced by more concise and better languages. It might not be Go but Java has just too much cruft to drag along into the future. Java will be around like COBOL is now. It might still be working, and some will always love it, but better languages are here and Go is one of them.