WordPress 2.5.1 was released on April 25, 2008.
That was 5937 days ago.

The iPhone didn’t have apps, multitasking, 3G, or cut-and-paste.
(It did, on the other hand, have AT&T.)

For background, you may want to check out this post.

@nacin and @koop think you should update, but they might be a bit biased.