I'm not sure they ever really think of it in anything but the most superficial terms. Hell, I just know the periphery of asexuality and still know that asexual people will occasionally have sex despite having no desire for it. As I said before; to my understanding, asexuality is determined by a lack of desire for sex/lack of a sex drive. However, a lot of these people think you can want to fuck everything in sight and have an uncontrollable urge to get off ten times a day and yet still call yourself asexual through some form of mental gymnastics that only they know. Frankly, I think it's stupid and belittles/marginalizes actual asexual people.