What item can you absolutely NOT LIVE WITHOUT in your saddle bags?

I have two...CHAPSTICK and a small bottle of insect repellent that can be used on either horse or human!

There are LOTS of other things in my saddle bags...but they I can live with out them. I keep my knife and cell phone on my body as may need either if seperated from the horse.

But can't stand chapped lips or mosquito bites.

What are your on trail MUST HAVES?