For the last week, I have not been able to get my hair into a decent bun for anything.  Somehow, on Monday it held together all day even though it was threatening to disintigrate from the minute I put it up. 

Normally, I wet my hair just a bit with water, chamomile tea or rosewater then twist and use a single hairstick.  I am twisting it just like normal, but it keeps wanting to untwist and fall down.  I don't want to twist any tighter than normal and risk hurting any hair, but I am not twisting any looser than normal either.  As soon as I start coiling it on the back of my head it begins loosening and unravelling itself.  My hair has never held onto barrettes or even scrunchies well because it is so slick that they like to slide right out.  But a bun was always safe and easy.  I have had it in a ponytail for a couple days.

I have no idea why this is happening.  The only thing I can think of is that my hair has been very silky/shiny/slippery lately.  I just senna'd on Sunday, I have been using a CWC routine with Suave and Herbal Essences.  I comb gently when it is dry and use jojoba oil.  I only use a couple drops and then comb it through.  I have been using the Ionic Hair Wand, which makes my hair very smooth, instead of my BBB which I think pulls out more hair and waves than the hair wand.   Since I have not been able to make myself stop washing it daily, I don't think I really need to use the BBB to distribute any oils.  In fact, I have been really happy with how it feels and looks lately.  Except for the bun thing. 

Does this happen to anyone else?  All of a sudden having your hair decide that your 'safe easy standby hairstyle' is just not going to happen? I do not really want to load my hair up with gel and hairspray, I only use those rarely for special occasions.  Does anyone have any idea why my hair is being uncooperative?  (Is it just bored? ) Or how to convince it that 'buns are good!^tm'?

I've had periods where I could not get a bun to stay.  I usually found it happened when my hair had grown a bit and the ends were no longer being caught by the hairstick.  You might try using a second stick or change the angle of the stick.

Good luck!

For aloe gel, I use as pure gel as possible (mine's 99.5% pure aloe vera gel, the rest is preservative). I've seen brands that claim to be aloe vera gel, but have a long list of other stuff in there too. Yuck!

Really small changes in length can result to hair starting behaving weirdly. A while ago I just realized one morning that I couldn't do a decent bun any longer. My hair simply had stopped cooperating- what happened to me was quite similar to what you're describing. Since then I've trimmed a little so that stage is again waiting for me in near future, but before trim I managed to do some experimenting.

Things I found helpful:

-Try another hairstyle. If regular bun doesn't work, maybe some other kind of bun (braided bun, figure 8, Leia's swirly bun, chinese bun etc.) will still work. Braids will always work. It might be that when the hair grows a little more, bunning will become easier once again. With some styles (not regular bun), gaining length may mean that one loses the ability to do that style permanently.

-Even if a straight hairstick won't work, a curved one might still work. I got best results with Longlocks spiral sticks. FuturiStix also worked pretty well for me- they have little dents in the surface and that makes them work well in slippery hair.
As BB said, two hairsticks may still work when one doesn't, and sometimes it helps to insert the hairsticks a bit differently.

- Or you could use hair pins in addition to hairsticks. Amish pins are the best.

Good luck!