Could just be you: Reference ranges are set for couch-potatoes and if you're a well-muscled man, you'll have creatinine high, often above the normal. And ranges are set arbitrarily to have a few percent of healthies outside on either end. Keep managing your hypertension and don't worry so much about creatinine.
A standard chess board has 64 individual squares, but 204 squares if you count squares of all sizes. A regulation board consists of eight squares in each direction.
The simplicity in stating and setting up the problem is also part of its appeal. A word of caution when introducing this task: Often students see this problem as somewhat trivial, counting just the 64 small squares; some go an extra step and realize that the whole board is also a square, for a total of 65.