[irishsultan]

Except titleize changes not the first letter of a string, but the first letter of every word. That's title case (https://en.wiktionary.org/wiki/title_case).

Capitalize (https://ruby-doc.org/core-2.2.0/String.html#method-i-capital...) on the other hand does something even weirder from your perspective, as it also changes letters to lower case.