You must unlearn what you have learned

For the longest time I have always placed two spaces after a period. I never thought this was wrong since this is what I learned while in high school. However, recently I have been researching typography and noticed many people saying that one space after a period is correct.

How was I supposed to know? I understand that two spaces after a period was relevant when typewriters were mainstream. I think I can say that the typewriter era has passed.

We are in the computer age and typefaces are no longer monospaced, meaning that letters do not use the same space length. The letter i takes less space than the letter m for example. On a typewriter, all characters use the same length. Because of this, two spaces after a period made reading the text much easier.

Look at a magazine, a book, or even online text. There are no two spaces, only one after a period. There are many proportional typefaces used now for web design and desktop publishing so two spaces seems too wide and may not look good.

I must now, as Yoda put it, unlearn what I have learned. It is hard to not place two spaces after a period. My thumbs are so accustomed to it that I have to think really hard to not place that extra space. At least you cannot see my mistakes since the internet only displays one space. This may take some getting used to since I was doing the two space thing while writing this post.