They call it "Autostick Gear Selection".
In Canada tap left to go down a gear and tap right to go up a gear. (When transmission is in drive)
Check your owner's manual and the other manual I got with car - Quick Reference Guide - for full explanation.
Again, I hope that this is what happened. Only once with me. Felt like idiot.
Just make sure that you are in drive D when you take off and that it is not a number for gear on instrument panel.
Again, just a guess that you had accidently put it in gear 1 or 2.
I leave mine in drive and don't use the "manual" way of shifting.
Good luck.