Hmm, easy question. How many stars do you believe there are in the original Super Mario 64. Note - You cannot count any images of the power stars in the game and keep it mind that there are 120 possible stars to obtain but actually in rumor more even though they are not counted as "actual stars"
From what I have played, I count 121 stars in Super Mario 64.
The other star that is not counted is the star which when is obtained after beating Bowser 3. A big star appears in the world which you can obtain by touching.