This has changed over time. Probably simply because of the internet. It used to be harder to expose yourself to the variety of ideas and perspective that college did.

It's hard to find opportunities for this outside college. Most people are not interested in intellectual talk, so the question is how to meet like-minded folks? I can't seem to find better alternatives to universities, for both number and diversity of opportunities. Book clubs seem like the best option but are often too narrowly focused on literature.