Humans are creatures of habit and if you start the tennis habit you'll find that your life and routine incorporates a number of places into your weekly schedule. If you notice that you aren't visiting these places or doing these things then you can admit you're not a committed tennis players.
Tennis Courts
Backboard
Weight Room
Stretching Mat
Tennis on TV or Online
People visit 25 places regularly - new study on HABITS
Make your habit tennis and you'll find that at least five of the places you visit have to do with the fact that you are a tennis player.