Periods of complete fluency

Periods of complete fluency I remember a period of about 3-4 days a few years ago where I was almost completely fluent, I have no idea why, the circumstances were not special, nothing stood out to me as the cause, I honestly felt like my time was coming, that I would finally be free, but then like clockwork it was gone. I’ve had similar experiences like this but never with the level of fluency I had there. Has anyone else had an experience like this?