I do that too and most of the time it leads to good conversations.

Sometimes it gets awkward though and that is when the other person is really, really excited about what they do. If I just show my honest interest I feel disappointment on the other side that I do not share the same enthusiasm. On the other hand I can't be frantic about something I didn't even know existed a few minutes ago. Positively interested yes, but really, truly emotional no. Faking excitement doesn't make me feel comfortable either.

Do you have any experience with that situation?