I react poorly to caffeine, and avoided it almost entirely for many years.
Then, I had THAT job, and I tried everything I could think of to stay awake at work, which included coffee consumption. The negative effects (jittery, anxious, loosing sleep at night) were still there, but I fell asleep slightly less often at work. I figured that my sleep at night was horrible at night even without the caffeine, so it didn't make much of a difference.
Then, I discovered a coffee shop with an amazing Cappuccino. I started drinking coffee just for the taste.
Then I lost the job, but kept going to that shop. A month later, I gave up on trying to live there, and moved back to my home state.
Here, I haven't found anything nearly as good, but I kept at it for a while, before deciding that the expense and effects just weren't worth it.
I'm weening myself off of it. Only very rarely will I have a coffee during the week, and even then, decaf only. On Saturdays, at my D&D group (AKA, the big block of "not alone" time which constitutes over half of my socializing during the week, so there's no way in hell I'm missing it or leaving early) that lasts until 2:00AM or so, I'll have 2.
I know it's bad to stay up that late and also to consume coffee for someone with sleep problems like mine, but no one ever wants to hang out outside of group events, and it's a group event where I'm more or less accepted, and it happens every week.