At what level in a language would you subjectively judge that you are

when you are finally able to understand everything you read.

For me it feels like magic, it's been so many years of not knowing. I keep expecting it to fail, that I will open a piece of text and this will be the time that I don't get it, just like it used to be before, and that I will have to use a translator to get the full context. It only started happening recently, in the last few weeks, after several years.

Would this be a B2 or C1 skill? C1 feels so high, like something I could never reach, but maybe I can dare to think I've reached it at least in reading.