I accidentally turned on talkback in the Accessibility menu. When I turned it on I got some kind of walk through on how to use it. I couldn't cancel it. So I turned off my phone.
When I turned it back on again it took me 15 minutes to unlock my phone. Apparently I had to touch a button to give it focus and then double tap it to click it.
Now my question is: how do I turn this off? I can't reach the settings because I have don't know how to access a drop down and I can't scroll through all my apps.