The three is Jupiter, the sign of study and mastery. Such a person needs life to be filled with substance: creative work, science, engineering, music — a field that has depth to it.
What sets them apart is not the breadth of their interests but their attitude to level. Half-knowledge causes Jupiter something close to physical discomfort: if you take a thing up, take it up to professional command, otherwise do not take it up at all. So they go on studying all their life, and usually in more than one direction.
They pay for it in effort. Versatility here is not natural ease but a result: every field is won by work, and what looks like giftedness from the outside looks like years of labour from the inside.