I've seen a lot of posts and comments about the 50 character convention but I'm not sure I've ever seen a reason for that specific number. What is the reason for that anyway?

It appears to originate with Tim Pope: http://tbaggery.com/2008/04/19/a-note-about-git-commit-messa...

Reading between the lines, it seems that the 50 character limit is to accommodate commands like "git log --pretty=oneline" and "git rebase --interactive" on an 80 column terminal. He also recommends 72 columns for any subsequent text because git makes a left margin of 4 characters and it looks balanced if you also have a right margin of 4 characters (80 - 8 = 72).

As someone who actually uses an 80 column terminal, I appreciate this practice. Probably younger people with good eyes won't be able to understand the reasoning behind it ;-)

> Probably younger people with good eyes won't be able to understand the reasoning behind it ;-)

Serious question, have you tried reading glasses? You don't have to just deal with bad eyes as you age, you can wear reading glasses. This what I do now.