I was a newbie last summer (a re-newbie, because I used to ride a bike a lot during high school). You could tell I wasn't one of the "cool kids" yet because I didn't wear a jersey - I was in the "t-shirt club" still. You could tell when I fell over 3 weeks in a row from my clipless pedals (although it was only on group rides). The constant refrain of "On the left!" as every other rider would pass me. Except that one time when I passed a very senior citizen on a vintage 3 speed bike.