I can be spoken, but never said. I can be written, but never read. I exist only when you don’t look for me. The moment you find me, I vanish. What am I?

A biological elevator, its passengers water and sugar. Or a category for the maths and sciences.

I move without feet, I grow when shared, I die if locked away, Yet I’m never alive.

I am taken before I am given. I exist only when measured, yet measuring me changes me. I can be saved, wasted, killed, and stolen, but I cannot be touched or seen. What am I?

What am I? To find out, first follow a curved line. Then, find some honey there. That's it, you should have all the information you need now!