Relativity is a complicated thing… Personally, it’s incredibly humbling. When I really sit down and contemplate the theory, I become totally aware that this is something I could have never come up with on my own… not even close. In fact, even with every piece of supporting information at my finger tips, I still can’t completely wrap my head around it.
If you’re in the same boat then check out the aptly named www.spacetimetravel.org. The site takes a more visual and intuitive approach to relativity, appealing to whatever learning style works best for you: