Every transition of a child is special and emotional for a mother.  Be it weaning, transition from bottle to sippy cup, going to playschool for the first time, from playschool to full-day school, switching from tricycle to bicycle, from pencil to pen, from four-line books to single line books.  I have crossed these stages for my son but still got tad emotional (I know its foolish) that finally he is in class 8 now and hence transitioned from half pants to full pants in his uniform.  Its symbolic of him transitioning from being a little boy to an adolescent which like all the transitional phases is a mix of being emotional, proud, happy as well as challenging for a mother.