I quit cold turkey and had bad headaches. What helped for me was having a decaf coffee. Just one would make the headaches go away. So the jump from say 300 mg to 10mg of caffeine was somehow much better than 300 to 0.
I think Ruby is polarizing. It is the only language I have used that I feel a genuine dislike for. Other people I have talked to feel the same. Then there is a group who loves it.
For me that language is Python (well, and x86 assembler). Python just feels fundamentally inelegant and messy to me, in a way that makes it tedious to read and write. I'll work on it if I must, but thankfully I rarely must.