Prof. P.C. Mahalanobis recalled:

“ I used to take my tutorial work with Mr. Arthur Berry, Tutor in Mathematics of King’s College. One day I was waiting in his room for my tutorial, when he came in after having taken a class in elliptic integrals.
BERRY: Have you met your wonderful countryman, Ramanujan?
MAHALANOBIS: I have heard that he has arrived; but I have not met him so far.
BERRY: He came to my elliptic integrals class this morning (This was sometime after full term had begun, and I knew Mr. Berry had already given a few lectures on the subject.)
MAHALANOBIS: What happened? Did he follow your lectures?
BERRY: I was working out some formulae on the blackboard. I was looking at Ramanujan from time to time to see whether he was following what I was doing. At one stage, Ramanujan’s face was beaming and he appeared to be greatly excited. I asked him whether he would like to say anything. He then got up from his seat, went to the blackboard, and wrote some of the results, which I had not yet proved. Ramanujan must have reached those results by pure intuition. His facility in the theory of numbers was in a large measure intuitive. He made numerical conjectures, like other pure mathematicians. Many of the results apparently came to his mind without any effort. He was, however aware that a good deal of intellectual effort would be required to establish his philosophical theories.”