Spoilers follow for tonight’s season finale of The Flash.
As Flash was accessing the speed force and travelling through the wormhole he saw glimpses of his past, present – and future!
The episode also saw Wells reveal to Cisco that Cisco is a metahuman, which explains why Cisco could remember the alternate timeline. In DC Comics lore, Cisco goes by the name of Vibe, and was recently given a new set of powers possibly making Cisco one of the most powerful metahumans on the planet, which we now see seems to fit in with The Flash TV series.
Udpate: You can find all The Flash season finale Easter eggs here including more images, video and info.