This is the Escher cube, and I will teach you how to draw it.
Step 1: Weird Shape
just draw whats below first.
Step 2: L 1
Add an L ,like so
Step 3: Double L
Add 2 L's, like so. the first one is upside-down, connecting to the bottom part of the first l. the second has the upper part as tall as the shape, while the bottom part is the length of the top part of the first l you did on this step.
Step 4: L 2
add another l , like the pic down below. I can't explain because it is just... there.
Step 5: 1 Double Line
attach two lines to the structure, like so.
Step 6: L 3
add yet another l, like so.
Step 7: Challenge
just look at the picture and you will know what i mean.
Step 8: Border
border around it, like so. you are done!
Step 9: Memorize
memorize it. i took me 4 hours, and i have the brain of a 10-year-old( i am serious about this).