Water cooler talk is not friendship. It's too easy to feel "connected" at work, and then not invest outside of it...and then once you leave, you find people don't have time for you.
By all means, if you find shared interests at work, seek to build on them, but a relationship of convenience through work will likely end once the convenience ends. That is both an obstacle to leaving (and is often what "culture" really translates to), and a major downside if you value real friendships since it's not any sort of emotional connection, nor even a shared activity you both can continue to enjoy.
As others have mentioned, if you just desire peoplecolocated with you that you can talk to throughout the day, that's also achievable from any major city, regardless of where your job is. And, a real benefit is since they aren't working on the same thing, or reporting in the same hierarchy, you can be completely honest and transparent with them (albeit with a mind toward not breaching corporate secrets), which is more conducive to building real friendships as well.
