Abe certainly was older than 30 and was sent back from the future to the 'present' in Looper. Is there any information about the younger version of Abe? Did the older version meet the younger version at any point?
TL;DR : The writer never though about the who is younger version of Abe, so we may never know.
I had suspicion that Kid Blue was the younger version of Abe. I made some search and It look like I was not alone. I found this interview of Rian Johnson , the director and writer of Looper. He said that he "never thought that they were", but find the idea interesting. This indicate he didn't though too much about the younger version of Abe.
(The bold text is the interviewer's question)
One of the things I picked up on in ‘Looper’ is the relationship between Kid Blue and Abe. It’s very much like a son trying to win his father’s love. I think a big question for a lot of people watching it is whether or not they’re related.
I know! Or some people have asked…
Are they the same person?
Are they the same person, which is interesting to me. I never thought that they were. I don’t think that would work, but I think it’s really cool that people’s heads go there. That’s definitely the dynamic I was reaching for with it, to see that kind of older/younger, a different variant on that — a sort of variant on the same theme between them.