Because you're not the only one.
We all love our favorite heroes, we read as many of their comics as we can, and we spend a lot of our free time talking about them. We probably dream about them at this point. And after all that we're STILL confused sometimes!
Just look at this graph tracking all the relationships from the Marvel Universe:
How does anyone keep track?!?!
Seriously, my personal life is a mess but this is ridiculous.
That's Captain America on a dinosaur.
The recently finished Planet Hulk series is the one confusing me right now. I thought that story line had been concluded? But then this miniseries shows up and my favorite hero is riding a T-Rex and looking for Bucky like it's not weird he's dressed like a gladiator. I've read fanfiction that makes more sense.
(I love it though, it's precious).