The answer is no. Although there is no consensus, since, for example, Australia, like any island, is separated from the nearest continents. But we cannot call it an island, because its culture and nature are sharply different from all the others. Secondly, the area and population are large enough to call this mainland an island.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.