as mentioned, diodes only allow power to flow one way, normal incandescent bulbs are resistive loads and could care less which way they are in

 

I wonder how many people took bulbs back because 'they dont work' was why I posted what happen to me, bulb doesnt show a diode (schematic symbol) either

 

Very, very possible.

I think it is one of those "common knowledge" things for those of us that have either done it or read about it, but definitely not something that all the manufactures note on their packaging.

Very good point to being up and may help others in the future that read this now, or use the search function later.

 

Also worth noting that some LED bulbs have a rectifier built into the assembly so that they'll work either way. Others do not and must be installed the right way around.