um, am I the only one who still sees it going round and round? I can see it going back and forth if I want it to, but mostly I just see it spinning. Weird.

Holy shit what a mindfuck

Watch it once and then try performing a de-stressing exercise before watch it a second time. Many optical illusions are more effective on people who are feeling stress.

Veritasium did a vid on this. (youtu.be) Very cool.