Ah! So basically I fell for the fundamental attribution error.

Mountains make me happy. I love snowboarding and hiking on them.

My explanation (dispositional): This person is a sports fanatic since he practices such an exotic high-commitment sport.

True explanation (situational): This person lives in Vancouver, where this taste in sports is commonplace..

Since you'll be looking for a person in your own city, this misunderstanding of signals presumably won't be a problem.