I want to ask if there is 'private key day'? If there is none, please let us have one. We can choose a day on this forum for 'private key day', for the awareness of how private key is truly the real reason Bitcoin owners have full control on their bitcoin.
I've not heard of a private key day, so I don't think there's any, I understand your perspective, but the problem is the form this is going to take, it can't be via an avatar, signature or personal text, cause quite a lot of users wear paid ones. Having said that, the forum via Theymos always has something to mark April Fools day every year, could your suggestion take that pattern as well to create awareness on the importance of private keys? That seems like the only possible way imo.
I don't know if the admin will prioritize this at all, I know private keys are very important and I believe every Bitcoiner should know that as well, I've seen quite a lot of users stress that importance with: "not your keys, not your coins" either in posts or personal text, a day for it wouldn't be bad, is it too important, I'm not very sure, don't you think this suggestion should be in Meta?