There is hardly an erudite scholar in India who has not heard of mathematician Srinivasa Ramanujan. It is believed that even most young school children in India with some degree of interest in mathematics know all about his life as well as achievements. His stature as a national hero in India is unparalleled. These are some reasons which might induce viewers both young and old alike to watch this film about Ramanujan. However, major disappointment is one sentiment which would greet viewers when they finish watching this ambitious film which failed to deliver on many counts. Firstly, it is episodic in nature and fails to develop as a large cohesive entity. Secondly, watching 'The man who knew infinity', one might have the impression of watching several short films tied together as a finished product. Dev Patel is an absolute miscast as Ramanujan largely due to his inability to delve deeper into the great man's life. It is strange to note that Srinivasa Ramanujan's relationship with his wife when he was in UK has been presented as a love story ! If this was not enough to add insult to injury, an additional blunder was committed by portraying this famous mathematician's mother as a villain who did not care at all for his wife ! The true story of Ramanujan is missing from this film as it not at all about Ramanujan but everything which happened to him. By giving importance to secondary stories around Ramanujan, the real story of Ramanujam remained untold.