So, how much true information having a direct insight into someone's allegedly secret journal can have? Just how trustworthy any intelligence can really be now

So, how much true information having a direct insight into someone's allegedly secret journal can have? Just how trustworthy any intelligence can really be now? Who's to say it's not lying to itself after all... Now ignoring the metaphysical rambling, it's a training problem. You cannot really be sure that the values it got from input are identical with what you wanted, if you even actually understand what you're asking for...