Up until a few years ago, it had been decades since I had used public transit. Then gas prices went through the roof, then I noticed a bus stop by my house, then I gathered up the courage one day to hop on the bus just to see where it would go. After that I was sold on public transit and now use it regularly in my city and quite often when I travel as well.
It just makes sense to know ALL of your options when it comes to transportation. There may come a time when for some reason or another you cannot drive your car or get a ride with a friend, walking or riding your bike may not work because of the weather or the distance, and calling a cab may be too spendy.
So, take some time this weekend to get a day pass for your local transit system and ride the bus/subway/light rail/monorail/etc just for the fun of it. This will allow you to find out not only where the transit system can take you but costs/distances/times, how far you can get away from the city and into the rural/mountain areas, and provide some options/ideas for bugging out should the need arise.