I had the same problem trying to wrap my head around the double codom verses super thing.

It's all about 50/50's and 100's.

A homozygous parent passes on the het version of the gene 100% of the time.

A heterozygous parent passes on the het version of the gene 50% of the time.

50% of the makeup comes from dad, 50% from mom.

To make a homozygous, you have to inherit the het version from EACH parent.