The idea was simple. Create a div.
Add two 50% div's inside. Float them. Add clearfix to parent.

Everything was fine.

Noticed that one of the childs had a height bigger than the other. But due to an adaptive design, setting static heights did not work.

Simple fix. Add a height to parent div and set overflow-y to hidden.

It didn't work.

Tried using the legendary !Important (a.k.a. not important but important.) Didn't work. Set position to relative, set static height. Set the childs to absolute position with height 100%. Problem solved.

No. It. Didn't. Fucking. Work.

Tried every possible css combination could could fucking think off.

After 15 minutes (8 hours in dev-stress mode) realized the clearfix changed the div DISPLAY TO FUCKING TABLE. A TABLE. FUCKING TABLES CANT HAVE FUCKING HEIGHTS FUCK.

Anyway. 6 years after my first clearfix. I learnt something new about the code that saves my life every project.