That's why you never see their parents, that's why summer last forever,
that's why the sky is a weird color, that's why they're never seen
outside of the cul-de-sac. The children all come from different time
periods, Johnny and Rolf from the 40's, Naz from the 60'...s, Kevin from
the 90's, Jimmy from the 00's (anon was correct). They are trapped in
the cul-de-sac, which is made up of older houses because of its creation
in the early 40s, due to their best memories being created there.
http://x.datchan.org/index.php?title=Ed,_Edd,_and_Eddy_are_Dead_%28Theory%29
Some really crazy people on 4chan came up with these theories explaining a lot of child hood cartoons and movies.