If you drive on a lot of hills or are gas-pedal-happy, unfortunately, it's normal. But if it's not actually reading the correct level, something else may be wrong.
Just be happy your gas gauge works. Mine doesn't. I usually go by trip but I can tell by the way (sound) my fuel pump primes when I'm low on gas. Or if it cranks for 10 seconds and I sit there slamming on the gas pedal praying for it to start.