This isn't hard. If I'm 35, then I'm 35. It doesn't matter what my driver's license says. It doesn't matter if I don't have a driver's license. My age is a fact in itself, apart from any documentation proving that fact.
Okay, so you are 35. How are we to know?
If you are a pathological liar you will believe whatever suits you and not necessarily truth.
If you are schizophrenia your fact is, again, whatever suits you at the time. Then may believe they are 18 years old - it’s a fact to them but there license may say 25.
If someone is color blind and they are going to wear there blue suit - it’s a fact to them, that’s my blue suit when in reality, it’s black.
So anyone person having a ‘fact’ unto themselves exists only to themselves - and, basically, any pig can fly w/that kind of existence. It’s ONLY a fact to them - in their OWN mind and it has nothing to do with reality until it is proven.
Things can be anything to one person - fact or fiction. They can call it a fact all day long and it doesn’t not necessarily means that it is - only to them - and nothing to do w/reality!