And Vipassana may be practiced at any age. There is nothing which can be called particularly Buddhist in Vipassana meditation. There is no element of religion. It is a scientific investigation and examination of yourself. You just observe closely every thing that comes to you and is happening to you in your body and mind at the present moment.
Meditation involves control of mind and mind is most unruly.
You come to know this personally when you practice meditation. So it is not easy to practice Vipassana meditation because it is not easy to control the mind, to keep the mind on one and the same object. In another way, Vipassana meditation is easy to practice. There are no elaborate rituals to follow or much to learn before being able to practice. You just sit, watch yourself and focus your mind on the object.