User blog comment:Gifist8/How Did ??? Become Savitar? (SPOILER ALERT TO FLASH EPISODE 19)/@comment-31390111-20170503165810

I myself think it's a time remnant that Barry is about to make to fight Savitar. Like his future self said, "You are going to make a bunch of time remnants and he's going to kill them all". What if he left one (accidently or more likely on purpose), the one that becomes Savitar. He could have been alone for all these years and around gone on a different way that 2024-Barry went on. Seeing that the only way he could be alive if there was the threat that Iris is going to die. Since that is the reason he's making those time remnants.

Also 2024-Barry could not have known if he never travelled to his future Barry and never got the hint about the time remnants.