...don't you need to be 25 to get the ATP in the US?
Negative, age 23.
I think the original poster was a tad....optimistic, shall we say, about his prior expereince.
At one time, long ago, I personally was the youngest expat Captain at SQ, on the B707, at age 28.
The CAA there checked very carefully on my experience, telexes to the various companies, DGCA's etc.