Lead footing is a phenomenon exclusive to automatics. Basically, you are on a 35mph road maybe, you lead foot some, the car shifts from third to the overdrive gear, now you are going like 45 or 50mph with the engine barely making any noise, you thinking this is just fine. On a manual, you'd know if you were in third and went to 50mph—the engine would be howling at another couple thousand rpm depending on the car. Going into your overdrive gear would require a conscious effort to shift into it.