Heh, so you go solipsizing (is that a verb?) even beyond actual solipsism?
Whether solipsism, or your particular brand 'extreme solipsism', thinking this way can be a good mental workout, I suppose, as well as kind of fun, once in a while: but are you saying you do this all the time?
Long answer:
A skeptic is skeptical of how all words work including "I" and "exist". "I think, therefore I am(exist)" on closer look works like a tautology. It ends being irreducibly true for the content, but empty of all other aspects. Here is a classical approach of a solipsist - I exist and I have experiences. It doesn't follow that if you have experiences, that they are yours. You might not have them, i.e. they are not yours, rather they come to you. If they come to you, there is something else. The answer, that is given by the solipsist, is that, this is my subconsciousness. But that is not "I", that is something else, otherwise it wouldn't be sub. So a solipsist in practice has a 2 factor model, "I" and "something else". I call something else the rest of reality. A solipsist calls it my subconscious, but it is not the solipsist's to own, but she doesn't control it. I don't control reality, I am a result of reality and "I" is a epiphenomenal property, which itself has no causal powers just like the mind. I don't have a mind, this brain causes I and the mind and this brain is caused by something else.
So I am the exact opposite of a solipsist, A solipsist treats "I" as fundamental, I treat "I" like an illusion, which works.
Now for the word "know". I am old school back to Agrippa's Trilemma. No one has Knowledge with reason and logic, because everybody ends up running into Agrippa's Trilemma. So I state what I believe. Some beliefs I can term knowledge but they are really beliefs, I don't check anymore, because they work for me and my interaction with "something else"; i.e. my belief in the rest of reality and that it is independently of me as it appears to me. I.e. the computer screen in front of me is there as something different than my and it is a computer screen in "itself"(Kant versus a Boltzmann Brain universe). Do I Know this? No, I don't and I don't care because I don't need to believe in Knowledge. I don't need to Know as some people need to.
I agree, this kind of over-generalization it might be wise to guard against, both in oneself and in others.
But I’m not sure I see the relevance of this in the context of what we were speaking of?
Look closer! If cognitive relativism holds for the subjective parts of reality and only the objective parts are fixed as the same for all humans, then for all of reality, there can't be an universal, absolute and objective as independent of human cognition model. So if someone speaks for all humans as for what reality is for all humans with universal reason, logic and evidence, it can't be so.
I.e. logic has a limit, "It is impossible that the same thing belong and not belong to the same thing at the same time and in the same respect", but says nothing about another thing. It can be wrong and right to kill another if it involves 2 or more humans' POW. As for reason, it can't decide in an unbiased sense a bias for or against something, it can change it between as for or against something. E.g. that objectivity is better than subjectivity is a bias in favor of objectivity and against subjectivity. And you can't decide between good and bad using observation, because observation can't see neither good nor bad.
In the end all one factor claims of what reality is, are subjective, because they are over-reductions of reality. Several humans can respectively believe in e.g. the FSM(there is One god), scientism(there is One form of facts) and objective communism(all answers can be derived from a(One) material condition). The same goes for that all laws of the universe are fixed in One sense; they all can't be, because then diversity(biological evolution) in human behavior would be impossible.
Reality is the set of a multitude of factors, which doesn't add up with reason, logic and evidence. I.e. reality is the set of X, Z, Y and so on, but the "and" is an "and" of a list and not a logical "and". The list doesn't add up with reason, logic and evidence.
To be a skeptic in these debates is to state the limitations of human understanding; there has in all of human history been no one System of reason, logic and evidence. Neither in science, philosophy nor religion, i.e. there is no single Truth or Fact.
What reality really is a single sense, is a belief, no matter what specific sense we are talking of.
Reality is at a minimum for you a 2 factor explanation - you and the rest. The rest then includes several facts and indeed you are not even one single factor. Reality is a lot of stuff going on and it doesn't add up. So I have stopped to claim that I Know with reason, logic and evidence. I state what matters to me.