Recently I have had people asking me why I "choose" not to have sex after they have found out that I am asexual. There are several things wrong with this question. Asexuality is not the same as celibacy. Now it is understandable why someone who is not asexual would be confused by this- we live in a sex-obsessed society after all, with little to no representation of or information about what it means to be asexual. I'd like to clear up some of these misconceptions one may have about the differences between the two.
First and most importantly, asexuality is not a choice. It is a sexual orientation (or maybe, the lack of, depending on how you view it). Like hetero- or homo- (or bi-, or pan-, etc.) sexuality, it is not something that can be controlled. Who a person is or is not sexually attracted to can not be decided at the snap of their fingers.
Celibacy, however, is a choice. It's a lifestyle decision generally based on someone's religious or moral values, though it can be made for other personal reasons. Someone who chooses celibacy has decided to give up sexual relationships, regardless of who they're attracted to. Their choice of celibacy makes it so, however badly they are tempted to have sex with an individual, they are not allowed to do so. Right here is the integral difference: an asexual, while generally not sexually attracted to someone, can still be willing and able to have sex if they so choose.
A (very basic) definition of asexuality is someone who does not feel sexual attraction to any given person. Asexuality is, of course, a spectrum holding many people whose sexualities have varying definitions, but the one I stated is the most general.
Nowhere in the above definition does it say an asexual can't have sex. There are many reasons why they might have sex (to please their partner, it may feel good to them, they may be bored- among others), but it doesn't invalidate their asexuality. If a celibate were to have sex, it would break their celibacy.
It is interesting to note one similarity- both a celibate and an asexual can be that way if they had sex in the past (providing a celibate did so before their vow of celibacy). However, only an asexual would still remain asexual if they chose to have sex later on.
With all that said, to anyone who tells me (and this is a direct quote by the way) "I wish I could also choose to be asexual like you, it would make my life so much easier;" I didn't choose to be asexual, and it really doesn't make my life any easier (the reasons for that are for another article). However, if you meant to use the word "celibate" instead, I have some great news for you. You can choose not to have sex, don't worry about it!