Masochism alley...

That describes ASM exactly. At the time when I went to school for my electro-technical studies, a lot of lessons consisted of this kind of programming for Z80 based PLC's (Programmable Logic Controller). When compared to the high level languages ASM is very efficient in (not) consuming computer resources (depending on your skill). And I can tell you, the resources from a Z80 processor are sparse!
ASM should only be done by people that have an exact idea about the functionality of the software they want to create and have the ability to stick to that plan no matter what. Furthermore, they have to be able to think in such small minute steps to create any function readily available in a high level language.
If ASM still sounds like fun, go for it...else forget that you even were considering ASM, better yet forget what it stands for entirely! Asocial Software Masochist springs into mind (thank you for that one, Mouser

)