As Election Day approaches, President Obama is sharing a few important things about himself. He has mentioned more than once in recent weeks that he cooks “a really mean chili.” He has impressive musical pitch, he told an Iowa audience. He is “a surprisingly good pool player,” he informed an interviewer — not to mention (though he does) a doodler of unusual skill.

All in all, he joked at a recent New York fund-raiser with several famous basketball players in attendance, “it is very rare that I come to an event where I’m like the fifth or sixth most interesting person.”

Four years ago, Barack Obama seemed as if he might be a deliberate professor of a leader, maybe with a touch of Hawaiian mellowness. He has also turned out to be a voraciously competitive perfectionist. Aides and friends say so in interviews, but Mr. Obama’s own words of praise and derision say it best: he is a perpetually aspiring overachiever, often grading himself and others with report-card terms like “outstanding” or “remedial course” (as in: Republicans need one).

As he faces off with Mitt Romney, the Republican presidential nominee, Mr. Obama’s will to win — and fear of losing — is in overdrive. He is cramming for debates against an opponent he has called “ineffective,” raising money at a frantic pace to narrow the gap with Mr. Romney and embracing the do-anything-it-takes tactics of an increasingly contentious campaign.