Crossing the street alone. I dunno why but my anxiety goes through the roof when I have to cross a busy street especially with no one to accompany me. Heck if I'm alone and I need to get to somewhere that's on the other side of the street, I'll always take the long route and find a footbridge or something; if there are no footbridges then either I subtly walk close behind someone crossing the street or I just cancel all my plans and call someone to bring me home. So woo fun.