I do sometimes regret not taking the job because the people there were wickedly sharp and the tech sounded great, but in hindsight I'm not sure I would have thrived in a bank long term. I did a 3 month internship at Lehman's which I enjoyed, but I don't think I'd have suited a career in it. One thing I did get out of it was a total lack of fear around job interviews, if I could survive the 14 hours of interviews at GS and come out with an offer, then I can handle pretty much any recuitment process :)
1. An organization/industry can adopt each new technology only once. New technologies arise infrequently. Each time they arise, only a few people get to work on the projects introducing them. In other words, opportunities to leave a big mark are limited.
2. Credit for innovation is political capital. People hoard political capital and become powerful. They act as gatekeepers of innovation and take the credit for successful projects.
Second fun thing. Kirat was advocating for lisp for secdb for a long time and used to rag on me for liking python when it's so slow.