I forgot about this effect given that it's been so long since I last "practiced." I suspect what happens is that my normally very anxious baseline is made less anxious so reaching familiar levels of excitement/anxiousness requires even more caffeine. Or exercise induced fatigue sops up the excitement juice. Does anyone see a similar effect from their exercise?

I couldn't find much online that corroborates this. These folks have the opposite experience. Most of what I find online are yoga blogs encouraging yogis to not consume caffeine because it interferes with flexibility.