I do that too – count steps, I mean. I always count stairs, because I like for my body to be symmetrical in its actions. even numbers of stairs are preferred by a longshot. When there's a set of odd numbered stairs, I remember which foot I used last, and use the other one on the next set.
 
There are 72 stairs from the ground floor to my 4th floor lab. 2 sets of 22 (split into 11 each) from floor 1 to floor 2, and floor 2 to floor 3. Then another set of 11, followed by a set of 17 (for a total of 28 stairs between floor 3 and floor 4). Thankfully, they all add up to be even at each floor. 🙂