Washington begins his farewell address by getting the primary business out of the way: telling people he's not going to be president again. It's a long sentence, but it gets the job done:

The period for a new election of a citizen to administer the executive government of the United States being not far distant, and the time actually arrived when your thoughts must be employed in designating the person who is to be clothed with that important trust, it appears to me proper, especially as it may conduce to a more distinct expression of the public voice, that I should now apprise you of the resolution I have formed, to decline being considered among the number of those out of whom a choice is to be made. (1.1)

Basically, there's an election coming up, and he's not going to be one of the options on the ballot. To him, this seems like a good time to break the news to America.

Sometimes people bury the lede, hiding their main point or big news farther down in order to build up to it. Other times, you put the main point up front, like in a thesis, and that's what grabs people's attention. Washington clearly opts for the second option, and he uses the rest of the speech to talk about his feelings about retirement and what ideas he wants to pass on to the American people before he's out of office.

At least he doesn't keep us in suspense.