I don't know if it's just me, but I have tried doing barrel rolls.
They are hard.
Actually a barrel roll is a normal forward roll. It got it's name because if you make proper form it looks as if you are inside a barrel, rolling on the ground, pushing yourself against the inside of it so you dont get slammed around.
But I agree with what you meant, while rolling forward and backwards can be mastered in 15 minutes, rolling sideways is incredibly difficulty to do. Especially quietly.