Board Thread:Questions and Answers/@comment-98.237.16.119-20151023070346/@comment-3423279-20160423173105

We have history books in the present day.... maybe Eobard read one and became obsessed with The Flash and eventually replicated the accident that made Barry fast.

Eobard then time traveled to 2020 or whenever and discovered he was to become the Reverse-Flash. That whole we have been fighting for centuries thing might of been hyperbole.

Speedster no doubt age slower, but I doubt that Barry remained youthful over 100 years later, if he was even still alive at that time and hadn't died from old age or something else.