Corns are a frequent problem on the foot. They are a natural reaction to pressure as the skin thickens up to protect itself from that pressure. At some stage this process goes wrong and gets so thick that it is painful. There's a continual myth that corns have roots which they carry on growing back from whenever you try and take them out. This is just like the analogy of plants that grow back from their roots if you cut the top of the plants off. This analogy continues to be applied to corns since they keep growing back, however they do not have roots to grow back from.
Corns originate from pressure and a skilled podiatric doctor can easily get rid of a corn. However, after the corn is taken off if the pressure that caused it is still there then, of course, it will grow back. It grows back since the cause continues rather than because the podiatrist left a root there for it to develop back from. That pressure might be from a poor fitting shoe or from something similar to a claw toe or hallux valgus leading to greater pressure on an area. If the corn is under the foot, then the cause is greater pressure on the area where the corn is, probably due to the way you walk.
The misconception remains simply because they do come back, so its important to remove the cause when the corn is taken off. There isn't any root to be removed. This means that the pressure on the foot the location where the corn has been should be lowered or removed. This can involve issues like using better fitting shoes or the use of padding to get pressure off the location where the corn is. Occasionally surgery can be required to the bone beneath the corn to remove the pressure. If that cause isn't eliminated or reduced then the corn will come back, so it will be easy to understand where the myth concerning corn roots originates from.