you dont have to roll the bike, just let the clutch out a little bit to where it starts to grab and shift and it will go into the gear u want to so u dont look like an idiot rolling your bike back and forth.

 

I don't think I've done that since my rookie days. No worries though. I usually use engine breaking anyway so I'm always in theright gear. The rare times that it does happen to me, I let the clutch out a little then shift down. Works in cars too when you can't get er in to gear. You always want to be in the right gear incase some dill whole doesn't feel like slowing down behind you and you need to get the heck out da way. Watch them mirrors.