Imagine the longing of a diabetic who is forbidden to taste any of the delicious cakes placed in front of him. His longing will be such that he would say to himself,
If only I could!
Such should be our love for the Sunnah of our beloved Prophet Muhammad صلى الله عليه وسلّم that we should have a longing to perform even those Sunnats which are impossible for us to perform i.e. tying a stone to the stomach during extreme hunger.
From a talk by Shaykh Muhammad Saleem Dhorat