Sometimes

Francis (age 2) describes things as happening "sometimes" that leave you wondering what happens the rest of the time, as in, "Sometimes, I wear pants at the airport." Really? Shouldn't he always wear pants if he's at the airport? I want to ask what happens the rest of the time. Is it that he only sometimes goes to the airport? Or does he think he sometimes runs around naked at the airport or wears a dress or pajamas? Or does he just mean he takes them off to go potty? Maybe he used to wear a diaper, but now he doesn't?