You are wrapping yourself in knots. (By the way, my sympathies for you in the sad loss of your mother.)
As you said before, it is very easy to have something you Think is a Proof... when it isn't.
So when you say that you have something proved to you ... how do you really know? You can't "never really know" one moment, and then be suddenly assured of the validity of a proof on another day in another situation.
Belief is what you hold to be true - - regardless of the validity of the "proof" or not.
Knowledge is the correct apprehension of facts, whether you have derived the facts from sound science or not.
If someone tells you that you need to boil a poisonous root 3 times before you can eat it, and they know this because of a nursery rhyme they were taught .... is that really knowledge? Sure ... if it is correct.
And in the long run, your semantic point you keep trying to make really doesn't change the discussion by much either.