Why does honey become crystal like?

The main reason honey doesn’t go bad is because of its simple composition: honey is primarily sugar mixed with a little water. This natural, low-moisture state deters bacteria and yeast, The sugary substance’s inherent dryness can also lead to crystallization, the process that causes honey to become thick and cloudy. Crystallization, which can occur anywhere from a few weeks to a few months after honey has been bought, can be remedied by placing the honey container in a bowl of hot water for a few minutes.

I don't know the actual reason, but it will do this after awhile. Put the container into a glass of hot water, to soften it. Dump the honey into a micro-wave safe glass and nuke it. Keep watching it. Nuke maybe 10-15 seconds and stir. Keep repeating until all the crystals are melted. Let cool and pour back into original container. I usually wash the container in hot soapy water before I put the honey back in.

It should be fine. I've done this to my honey many times. Be careful, and watch it in the microwave-it can easily boil over and leave a horrible mess!