That was a great read, but there was one thing I didn't understand: Why would the regex string have "." twice in a row? What does ".." find that "." doesn't find? Does that just mean "at least two characters"?
It means specifically 2 characters, and is equivalent to .{2}
..+ or ...* are ways of writing "at least two characters".
A single `.` matches exactly one character. `..` matches exactly two characters (not more, not less).