Maybe my choice of the word "comfortable" was incorrect (although I would say "grok" was a spot on word choice in this context). It took me a good while to get the point where no matter what I encounter in TS, I feel pretty confident I can arrive at understanding it. The type system is very powerful and there are some deep rabbit holes you can find yourself in.

For example, if you can follow this blog post after only two weeks then you are much smarter than me: https://medium.com/free-code-camp/typescript-curry-ramda-typ.... This is a pretty extreme example, but sometimes you hit crazy types or crazy type errors like this.

But I would agree it doesn't take all that long to feel comfortable enough with TS to be productive with it.