The lonely caches page only shows the average loneliness of a Cache (see description on that page: "The loneliness is calculated by dividing the age of the geocaches (in days) by the number of finds.").
So there can be more days of loneliness between two finds than it is shown on this page.
I once had a challenge that required to find a cache which hasn't found for at least a year. I didn't find a way to search for such a cache in my finds. So I produced a list of all unfound caches around my homezone and sorted this list by last found date. There was one cache which hasn't been found for 361 days, so I waited 4 days, hoping that no one else would find it in these days, and then I went out and got it.
And on the lonely cache page this cache is shown with an average loneliness of 53 days...