Got this new fangled aluminium critter. It has 21 gears on a 3x7 config. I got a tad confused biking back from the LBS to work. I did take the critter for a spin on a vacant block but whence faced with some open road and a single vehicle I ended up at the other end of town before I composed myself enough to turn around and head back. So how long does it take the average Joe/Joeette to run through these gears smoothly without looking for the levers etc., blah, blah, blah?