Aging and sex drive?

I have found that in my mid 30's (36-38) my sex drive all of a sudden became no existent, but now ever since I have turned 39 it seems my sex drive is all of a sudden in overdrive, and I am now interested in experimenting in things that never occurred to me before and loving it. Is this a normal like hormonal body changing thing that women go through or is it just me? All the older women in my life (mom, aunts etc...) are kind of prudes and no help when trying to talk about whats going on with me and body.