User blog comment:Teag J. Brohman/I Just Realized Something/@comment-30458740-20180613005450

I've thought about that before. I think the reason Lisa did not encounter her "past self" is that after jumping into the wormhole, her subconscious was then transfered to the point in time she was that she's time-traveled to and then inhibited her "self".

That's my scientific guess anyway. Time travel is always a pain in the brain the more you try to make sense of it.