Learning to meter without light meter has its usefulness.
Learning to meter without meter can be precious especially for "street shooting" when there is no time to even look at the camera setting. You know that your camera is set at 1/125@f/11 (100 ISO). You see a subject standing in shade (EV 12). You turn your aperture ring 2 clicks more open, focus and shoot, mentally counting the aperture clicks, without looking at the values on the camera and without checking the in-camera instrument (which requires "reasoning", analysis of the background etc). Especially with B&W, street shooting can be just "turn 2.5 apertures more open in shade" and "turn 2.5 apertures closer" for sun, leaving the shutter speed fixed and operating the aperture ring with extreme ease and speed.
Ahh yess! The seemingly lost art of setting exposure as the camera comes to your eye.