TIP: The shortest distance in a city is not necessarily a straight line.
Living in or near a major crossing point of a city's transit system can give you quick access to a great amount of area.
If there is a transit line that connects many of your areas of interest, living by transit stops on that line may give you great access to what you need.
You can tweak your focus area map to reflect this by coloring areas according to transit time. For example, shade in red those portions of the map where a combination of transit time and walking puts you within 10 minutes of one of your focus areas. Color in orange those areas within 20 minutes and so on.