Transferring 1000 pidgeys
Ah yes, I can't even begin to explain how much of a relief it was to be able to finally get rid of the over 1000 pokemon candy hoarders I had stored waiting for a double candy event (way overdue). It was a pain managing my storage so that I could hold on to as many of them as I could for so long. On the bright side, I now have all the ralts, dratini, and Larvitar candy I will ever need, sitting at 2273, 1089, and a whopping 3279 respectively.
Woah, kudos to you for saving that much. You're set for life with those three species.
I wanted to comment since you said "way overdue" that no, it actually wasn't that much overdue. There have only been a few double candy events in the entire history of POGO and it was completely plausible that it would take 6 months to get the next one. I kept wondering why everyone was so optimistic that we'd get one soon after Halloween.