I remember during the last few episodes of season 1
"Wells" aka Eobard Thawne states that he is not born until 100+ years in the future (I don't remember the exact year). However, Eobard despises Barry/The Flash, which is why he went back in time to murder him (and killing his mother instead). Clearly there is a pretty deep hatred/rivalry that has developed at some point in the future.
Which brings me to my main question:
How did The Flash/Barry and The Reverse Flash/Eobard Thawne ever become rivals if there is such a large age gap between the two of them? Surely Barry would be dead by the time Eobard is even born.
As far as I can tell, this isn't explained at all during the season and no characters ever acknowledge the fact which slightly irritated me through the last episode or 2. Did I miss something, or am I supposed to have some sort of knowledge of the comics?