I just can`t get the meaning.

[zoobinshid]

Hello eveyone,
Would you please tell me the meaning of this sentence on the whole and specially this part(a wall that is no less impenetrable for being invisible)?

He builds a wall of indifference and remoteness between reality and himself,a wall that is no less impenetrable for being invisible.

Thanks in advance,

[twostep]

Hello eveyone,
Would you please tell me the meaning of this sentence on the whole and specially this part(a wall that is no less impenetrable for being invisible)?

He builds a wall of indifference and remoteness between reality and himself,a wall that is no less impenetrable for being invisible.

Thanks in advance,

He is closing himself off from reality; turning hermit.