When I was a kid, playing 1st edition, and had nothing better to do, I took a character up to 67th level (Paladin 33, Wizard 34, using the old dual-classed rules). I had a small group of friends, we played pretty much every weekend or more, and did this partly for the exercise of dreaming up advancing all the tables in the books.
Since then (that was probably around 1983 or so), I think the highest level I've gotten a character is my current one (16th); as a DM, I have a few 25th level characters running around in my campaign (and those characters have been played since 3.0 came out, give or take a few months).
Now, I get that some people have the "I can one-up you" personality type completely saturating their synapses and genes, but, really, 256th level? All the way from 1st? Really? Do they eat? Who are these people?
Dave