> It’s important to note that the actual numbers you use to mark the list have no effect on the HTML output Markdown produces.
It does cause a lot of surprising errors though, especially when the person isn't actually trying to write a list. For example, a case that comes up often is that someone will ask a question like, "when did this happen?" and someone will reply something like, "1986. It was a rough year." But due to markdown interpreting that as a list, it will get rendered as "1. It was a rough year."
Causes a lot of fun and confusion around ages too when it looks like someone's saying their child/significant other/etc. is one year old when they really typed a completely different age.