The title says it all, My friend and I were discussing how Greg Universe talked in Jail Break as though he had seen the war between the Crystal gems and the Homeworld gems. Some have theorized that this would make Greg 5000 years old but we have a theory. What if the War had actually been going on in secret for the past 5000 years and was only won just prior to Steven being born. This would mean that in his life time Greg would have actually seen battle.
Cconditional of course is the understanding that humans have only had the technology to even know about gems for the last 100 years. It would solve many conflicting plot holes and arguments over the internal timeline. Nobody in the series said the war was WON 5000 years ago, just that it started back then.