ES Recruitment Drive
There was an auction by one of the admins/ devs (I think it was fish) quite some time ago and if you won you got a green hat that was positioned on the head of your avvy.
Life's not a waste of time and time's not a waste of life so let's stop wasting time, get wasted and have the time of our lives - Mr Worldwide 3:18
Before the Green Hat item was released, Fish was doing an auction on the forums
for the Green Hat over your avatar.. The winners of those auctions got the Green Hat
on their avatars and were given a Green Hat item upon their release.

I don't think there is any way to get them anymore.
The past makes you wanna die out of regret, and future makes you depressed out of anxiety. So by elimination, the present is likely the happiest time.