You certainly can't if you don't try. On the other hand, it's a nice skill to have for lots of applications. You don't need to get massive air but it's handy for riding up a curb (lofting the rear wheel saves wear and tear) as well as riding down a curb (where lofting the wheel also saves wear and tear).

It also comes in handy if a pothole suddenly appears in front of you because you weren't watching where you were going. It's also extremely handy if you are "adventure" biking or off-road touring.