Just One Of Those Things …
Quiz time. Which is correct?

(1) Hafizah is one of those rare people who love grammar.
(2) Hafizah is one of those rare people who loves grammar.

It may be something of a surprise that (1) is technically more correct. Most speakers, however, would prefer (2), presumably because one appears to be singular. But the way to look at it is this:

Hafizah is one of X.
X = those rare people who love grammar.

Now it is immediately obvious that the relative clause who love grammar postmodifies people — hence the plural verb, love. The scope of the plural people applies only within the embedded noun phrase, as indicated by X, and does not extend to the larger sentence. Now consider this:

One of the books you ordered has arrived.

This is correct, because the head of this noun phrase is the singular one.