That strange and unique way of his, to express himself in terms wonderfully adequate for his thoughts, no longer surprised me.

It was often necessary to know his thought to understand the terms he used; and it was not easy to penetrate into Rouletabille's thinking.
This lad's brain was one of the most curious things I have ever observed.

Rouletabille went on the even tenor of his way without suspecting the astonishment and even bewilderment he roused in others.

I am sure he was not himself in the least conscious of the originality of his genius.

He was himself and at ease wherever he happened to be.
When he had finished his recital he asked me what I thought of it.