People love to talk about themselve and what they are doing. Ask questions about people and be genuinely interested in the answers. Remember what you learn.

Remember that software isn't the only "technology" (in the original sense of the word). Every discipline has its technologies (farming implements, business accounting practices). It can be fun to learn about those.

Also, if you've been developing for 20 years you probably are a systems thinker. Seeing similarities in business and technical systems (and comparing and contrasting them) is pretty interesting and can lead to some good discussions.