To be fair, I know enough first aid and background information to understand some basic medical books, and I can 1000% guarantee that you never want me to treat you for any medical problems.

Eh, lots of stuff can be easy to learn, difficult to master.

Most languages only take a few minutes to do a "hello world" app.

When you announce you're comfortable with something, it probably depends on the scale of the apps you're used to working on.

So a junior dev could very well feel they've learned something like react after two days of cramming.

Me too, but I wouldn't claim to know React unless I felt good at bluffing.