A query I ran yesterday isn't in the plan cache, but older and newer ones are. Why?

Yesterday, I ran a big ad-hoc query that I didn't save. Today, I want to see it again. I thought that I'd hunt through the plan cache. To my surprise, I can find older queries and newer queries, but not the one that I ran. Why might this be? I know that I should have Query Store turned on, but I haven't done it yet.