How good are you
I used to say I was "ok" at playing pool.
Then I played someone. Afterwards they insisted that I start declaring that "I am really, very quite good at it".
It is only fair to other people, they said.
The next time I was asked how good I am, I answered: "I am really, very quite good at it".
Turns out, no. This new competitor: They were truly, really, very good at it. I was rank beginner next to them.
So now my answer to that question is always: "Compared to what, and to whom?"