Introduction to Special Relativity

Special Relativity is hard to understand. I was stopped by it in university, and was confused by it once more recently.

If a globe can be put in every classroom to show that the Earth is round, why can't we do the same thing with Special Relativity?

If a theory cannot be understood after 100 years of its publication, there must be some reason. Either the theory is wrong or no one really wants to understand it.

In the following sections, let's go through the twin paradox, and see if it can lead us to anything.