I've always known how to draw. I don't remember a time that I didn't.  Even when I was in kindergarten I drew figures in correct proportion.  People told me that I drew well but I didn't think much of it.  I really believed that anyone could draw if they put their mind to it or if they liked.   Being able to draw was very helpful in school because many projects involved art, even science where drawing of specimens was frequently required.  I never seriously considered pursuing art as a career.  Instead I studied biology in college and graduate school and then worked in the field.  During this time I did not do any art. 

     When I was in my forties (yes years) it occurred to me that people in general should develop their natural talents (duh.)  So, I bought some art supplies and began drawing on my own at home.   Within weeks it was clear to me that I should pursue art seriously and, also, that art is a full time job.  So, I quit my job (yes I really did) which I liked a lot, took some classes at a local college and have not looked back.  At this point in my life I can tell the difference between learning how to do something and just knowing, i.e. that being an artist is a gift.