Have you ever been so obsessed with something that you just couldn't stop using it?  Let's say the object of your affection was...peanut butter.  You loved it so much that you ate it with literally EVERYTHING.  After months of eating peanut butter, you start to hate it.  Suddenly, the sight or smell of peanut butter makes you gag, so you stop eating it.  Then, about a year later, someone offers you a peanut butter and jelly sandwich and you meekly accept.  Once you bite into the sandwich, you fall in love with it all over again.  You wonder why you ever stopped eating it and re-introduce it into your diet.  

The same thing happens with hair oils.  You may be obsessed with an oil for months and one day, the oil simply stops having the same effect that it once used to have on your hair.  By simply using a different hair oil every 3 - 6 months, it will ensure that it provides the maximum amount of effectiveness.  

Do you rotate your hair oils?  If you do, how often do you rotate them?