Blue lines are parellel. Goodluck convincing that to your brain

In a certain angle I see them parallel

Pretty easy
Just blurry everything on purpose or take off your glasses if you have them on
You wouldn't see the black and white lines anymore so

Not really hard to think about.
They don't have to be the same length, then just have to be going in the same path without crossing

Done... im not sure what is hard about this

If I focus, it doesn't fool me.

I just have to unfocus my eyes

Guys, just close one of your eyes

I did it by staring at the centre and forcing my brain to see it so