And I can say you can't understand General Relativity unless you understand Special relativity because general relativity is an addition to Special Relativity that came first, and that is why it is taught first.

Sure, if one wants to study dynamics, you first learn kinematics. If you want to study calculus, you first study algebra. But it's not the point of which comes first. Now imagine studying physics with just high school algebra. How much will you understand the laws of physics without calculus?

If one can't understand how things that aren't accelerating are relative to an observer, how can they understand that when they are accelerating they gain mass and time gets shorter as measured by an observer not accelerating, and that the length as measure by an observer standing still gets shorter when it's a lot harder to understand?

All of the effects of SR have been known for more than 100 years. SR, like Euclidean geometry, is a closed subject -- that is, we know everything that we can possibly know from it, and therefore, there is no active research being conducted in SR. Only crackpots and ignoramuses still question SR. The rest of scientists have moved on. The current research is in GR, coupled with thermodynamics and QFT.

Now in your case, you don't have the math, you refuse to upgrade your knowledge, you spend your time searching for websites to copy and paste, and then you want to discuss SR like a philosopher ruminating from his ivory tower. That's not how physics, or any other science, is done.

Now if I said to you that in GR, velocity as a concept is ill-defined, would you understand that? I think not. To come to that conclusion, you would need to study manifolds and parallel-transport. Or if I would say that in a Black Hole, the thermal radiation can destroy information, would you understand that? I think not. You would need to understand not only QFT per se as in how QFT gives you the Standard Model, but also how QFT is applied to GR, which is an altogether different field of research. And I can tell right off that this would be beyond your comprehension. It's not that I'm saying you're an idiot, it's just that I know you don't have the background to tackle these concepts. But you are an idiot IF you think you know this stuff better than I do.