Well, the longer the better. Experience is a teacher and with a person having a lot of experience then they can easily teach others since they are masters of tha subject being one's that deal with it always.
"How many years does it take to become a chemotherapist?"
How many years does it take to become a cytopathologist?
how long does it take to become a gerontologist?
It can take many years to become an overnight success.
It will probably take 7 years to become a music teacher.
How many years does it take to become a genetics if you start from AA degree?
4 years
10 years
it will take about 7 to 8 years
It can take anywhere from five to ten years of training to become a full Geisha.
It takes 10 years
5 years