Should I buy it ? Canon EF 50mm f/1.8 II Camera Lens?

i own a canon t3i now, I'm a beginner for photo and video making. Im already own a [Canon EF 35mm f/2 Wide Angle Lens for Canon SLR Cameras] and a [EF-S 18-55mm f/3.5-5.6 IS Lens]. I wonder should I get the [Canon EF 50mm f/1.8 II Camera Lens] because everyone said this is a good len to start learning photo and video for beginner. wat do ya think????? I'll do more video than photo.