Yes. Instinctively, more than a page of unbroken monologue seems a bit long.
As has been mentioned, it's usually a good idea to keep the reader in the situation, and aware of the characters by mixing dialog with action (even if it's just a suppressed yawn ;-).
How about adding a confidante that this character can have a dialog with? I find it very helpful and it's been done so much in literature and drama it would probably have been a cliché had it not had so many possible combinations.
Or, since you're retelling an event, try with a short flashback? It would go something like:
I told him about that early spring morning. My aunt had returned from Lissabon.
"Hey, there, squirt," she said.
Yes, it might double in size or more, and it would, of course, be better to make it into present action, but if you can't, a flashback might help.
Another variant, if you already have lots of action and showing going on, is to simply tell it as in: "I told him about that early spring morning and the boats and the goats and everything else and so on and so forth..."
By telling, you might be able to cut it down some, or a lot.
Or, an exercise:
Take a piece of writing you really like. For instance a dialog between two or more characters and remake it into a single character's monologue. Then compare the original and the monologue. You might get some hints.
(I actually tried to do the same with a piece from my WIP as an example but 1, it's not in English and Google Translate still sucks, and 2 it's unpolished, and 3, the monologue looked more like an insult to the original and that wasn't really what I wanted to say...)