A question regarding proof

[Fred]

Just plug an EEG machine to your head before you go to bed and you can prove you had dreams, even those that you yourself don't remember. Watching REM is also a good way to prove. As to what those dreams were about, we can't, at least not with the current technical capacity. So what's the point Fred?

Your EEG or an fMRI or any of the most sophisticated gear we have can track the brain activity, but it cannot disclose the content of the interior experience apprehended by the subject.

My point is that when it comes to evidence, the idea that only objective evidence is real or valid is not accurate, nor the whole story, and except as an ideal or a club to wield, in practice, nobody really believes it is.

The idea that evidence = objective evidence alone is wrong.