ivory tower

live in an ivory tower — жить в нереальном, выдуманном мире (в "башне из слоновой кости"); избегать общества; вариться в собственном соку

1. Many university professors are said to live in ivory towers. They don't know what the real world is like.

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"An ivory tower" is a direct translation of the French "tour d'ivoire" coined by the poet and critic Sainte-Beuve. He used it to describe his fellow poet Alfred de Vigny's seclusion in a turret room and de Vigny's preoccupation with inspiration unconnected with practical matters.

See [keep (oneself) to oneself]
[оторваться от коллектива]
[оставаться в стороне]