The pronoun ‘I’ is a capital letter. And when I finish my sentence, I put a full stop. Months of the year have a capital letter, a capital letter! Word space, word space. Dancing around all ...

Where did that come from? Actually, the real question is why we have lower-case letters. Originally, the Latin alphabet (and the Greek one, too) had only the capital forms. That's why when you see ...

There are more than one of them: 'friends', 'neighbours', 'house', 'party' and 'year'. And unless they're at the start of a sentence, as with 'Friends' here, they don't need capital letters.