In my pre-New Year tidy up and declutter, I have counted we have 35 unused Christmas crackers that are going back into the loft. At our current rate of consumption, these will last at least 10 years.
For context, I have never bought a cracker in my adult life! 
To be fair to DP, 24 are from clearing his parents bungalow (and made by Safeway so that gives an indication of how long this obsession has been manifesting in his family), however, he did buy a new pack this year when there were a mere 32 available to use but he "forgot" about them.
He also purchased 6 bottles of Baileys, two at a time, over the two months prior to Christmas as "they were on special offer" and he had "forgot" about the bottles he had already bought. I am less scathing about this as we will use it all (eventually 🥃😋)