I've never found any sense in the notion that a 50 mm lens, or any lens for that matter, somehow more closely corresponds to our eye than another lens. Personally my angle of vision is close to 180 degrees horizontally (i.e. I can peripherally see things directly to my left and right simultaneously). This is wider than any lens except the odd fish-eye. But my visual area of sharp focus is vastly narrower, similar to a super-telephoto. If I want to closely observe the letters in one of these words on the screen, I must move my eye slightly for each letter, such is the narrowness of my acute vision.
Then there is perspective. Perspective is not a property of any lens. The lens merely crops an area of the scene and records it on film; the perspective of that scene is determined by the subject to camera distance, and when viewing the print, the viewing distance and enlargement factor as outlined by Roger. However, I don't strive to manipulate the enlargement factor and viewing distance to "normalise" the perspective. In fact, I use a wide-angle lens precisely to allow me to shoot from closer, thereby stretching the perspective, which I make no attempt to "fix" in the print. In any case, with very wide lenses it's impractical to normalise the perspective at the print viewing stage because the print has to be so large and/or the viewing distance so short.
I very much enjoy shooting with a 50 mm lens. But I prefer the 35 mm. The latter offers excellent control of depth of field, from sharp everywhere to completely blurred backgrounds, in normal lighting conditions with normal film speeds. Wider than 35 mm and it's difficult to blur the background unless the lens is extraordinarily fast and the camera to subject distance is small. Longer than 35 mm and getting a large depth of field requires too much light or a tripod. I find the 35 mm just right.
