He doesn't know much about the real world because he's been living in a bubble.
Он мало знает о реальном мире, потому что живёт в своём мире.
Definitions
Living in a bubble refers to a state of being isolated from the realities or challenges of the outside world, often due to a lack of exposure to different perspectives, experiences, or information. This can lead to a skewed understanding of social, political, or economic issues.
