Sarah Palin’s career as governor of Alaska is over. So is her barely begun career as a serious presidential candidate. The road map to the White House doesn’t include a stop at “I quit.”

In a truly Palinesque moment near the end of her speech in Wasilla on July 3, the departing governor quoted a saying she said her parents kept on their refrigerator. “Don’t explain: Your friends don’t need it, and your enemies won’t believe you anyway.”

The governor might have done better to take her cue from another piece of refrigerator wisdom: “Quitters never win, and winners never quit.”

Palin’s speech was hastily arranged and hastily delivered. This was not Lou Gehrig’s farewell to baseball — simple, clear, humble, brief. Nor was it the work of the poised, fresh-faced Sarah who electrified the Republican National Convention in St. Paul, Minn.

The governor seemed to have trouble breathing — was on the verge of panting — as she took a long, clunky windup to make her pitch. She recited her achievements and chastised the media for not appreciating them. She told us how sorry she feels for herself and her family. She praised our brave troops serving abroad, renewed her commitment to the fight for free enterprise, denounced apathy, and explained she would not waste public dollars as a lame duck. And she dipped into metaphor, invoking her experience as a high-school point guard.

The point-guard metaphor was supposed to leave Alaskans appreciating her willingness to pass the ball. Instead, it raised an obvious question: “What kind of point guard walks off the court in the fourth quarter, refusing to play any more?”

Palin talked for more than 15 minutes and, keeping faith with her parents’ refrigerator, not once did she provide a convincing explanation of why she is leaving office.

We are left to guess. The only thing we can be absolutely sure of is this: Palin did not tell the truth when she said she is leaving for the good of Alaskans. She is leaving for her own good. With Sarah Palin, “me” always comes first. And with Sarah Palin, the personal and the political are never separate but totally intertwined. In fact, they are the same thing.

Why she left may be as simple as this: She couldn’t take it anymore. Palin’s thin skin is legendary. She never ignores a slight. For most of the last year, she has been feuding with the Alaska media and many of the state’s political leaders. She has almost no support among legislators, even Republicans. And she haphazardly applies herself to the labor of government at a distance — some critics call her the BlackBerry governor.

She will keep Alaska in the news. But she is finished as a leader. No leader abandons the battle in mid-fight.

How will she be remembered?

If she is remembered at all years from now, my guess is it will be in the same kind of way that we remember the Los Angeles evangelist Aimee Semple McPherson, who, in the ’20s and ’30s, drew massive crowds and vast media coverage until she disappeared for several weeks without ever adequately explaining where she’d been.

After that, she lost her magic and fell out of favor, leaving historians to ponder: “What was everyone so excited about?”