It happens to everyone sooner or later. Sooner, in the case of me and my siblings. A sampling of what we adopted:
Shannon: chilly barbarino, Tinkle Time, I LOVE MY FAMILY!, staring at the computer with one hand in front of mouth and nose
Sarah: chilly barbarino, clapping, giggling and squealing with delight when I get into bed
Brigid: Tinkle Time, a love of coupons (exaggerated to the nth degree), clapping
Kelly: repeating every single behavior from mom's youth
Patrick: 'comfy clothes', Popsy la Wopsy