ASSEMBLY

I've decided I'd like to try and learn assembly in my spare time.

But I want to know how hard it would be compared to learning C.

And also if you know assembly, how long did it take you to learn and how often do you end up using it?

Not really sure how threads like these go down on /prog/ but I figured here is the best place to ask at least.

I learned assembly back in the days of the C64 (6502 asm) and then got interested in Carmack's articles during the development of Doom.  He had to do all the graphics shit with 80286 assembly.