Not a silly question at all. One of the first things I swap out on a vintage bike is the handlebars. From the 60's and 70's the bars were somewhere around 38cm. I rode with 38's for years and I am a typical broad shouldered Chicagoan.

Wasn't until the 80's that I was able to find 40cm bars. What a revelation. The comfort was much improved. Then I got 42cm bars and again greater comfort. Now 44-46 is pretty common.

To throw another factor into the mix, I recently acquired a vintage Raleigh Super Course. It has what I believe is referred to as a Maes bend bar. It has a long reach, (long ramps), on the top of the bars. Measuring 36cm wde at the brake levers and 39 at the drop ends, I find them extremely comfortable. The long ramps give me multiple hand positions between the flat of the bar and the brake levers.