Did Jesus know how old he was? ( this question was proposed by the late George carlin)?

Like anyone else, Mary and Joseph would have told Him about the horrible journey they had to make to be enrolled at Caesar's command. That year would also have had a date so ,if it were a significant piece of information then He would have been able to calculate how many summers or winters He had lived.

Date of birth may have been of no significance to ordinary people in those days. However, it was generally known how long a ruler had reigned and when significant events in history occurred.

it was the Church that decreed that Jesus' birth should mark the transition between BC and AD. Our 2010 is the number of years since the birth of Jesus.