An experiment. Probably 2004.
What happens if you dress up as animals and walk around London for the day? Not handing out flyers, not promoting anything - just having a day out in London.
Short answer: school children will attack you, builders will defend you, pizza delivery men try to run you over, businessmen hug you, bus drivers don’t blink an eyelid.
Conclusion: London runs on autopilot, but there is no autopilot setting for meeting a giant teddy bear, so everyone has to make it up on the spot.