When your friends ask you questions or advices on how and why boys think and act in a certain manner; while you honestly have no clue and never understood those behaviours.... AT ALL! (mtf)
When your mother gives you her old clothes because she just has too many or simply thinks that they would look better on you.
When, before you officially started your transition, people on the train thought you were a girl; although you've never consciously altered your appearence.