I will not repeat the same thing which is already covered by others. Mera Naam Joker I would say Raj Kapoor's one of the finest work in his career. A series followed after Awara, Sree 420, and Jagte Raho. Infect in true senses he expressed his real tribute to himself, his career. Whatever he learned he put everything into this. The philosophy says "the show must go on" who knows more than an actor. So whether he is happy or sad or crying he should always look happy and never show traces of his personal anguish. Personally Raj Kapoor was inspired by Charley Chaplin's work and we get the glimpse in his early movies. His philosophy behind this movie is true and very natural. Lets discuss different stages one by one.
Episode I
Adolescent infatuation, his thoughts, his dreams are true and I must say everyone must have faced the same situation with his teacher when in school. His point here only depicts how a young developing mind fantasies. His gesture to present his idol joker to his teacher is a very philosophical thought that only a director like Raj Kapoor can think. He repeats the same with other two women and gets it back all the time.
Episode II
This version depicts the young and passionate love of joker Raju. He tried to show a person in this age group does not think anything other than love, he thinks for romance and fantasies. Here too joker loves, dreams and shows his innocent heart. Raj Kapoor gave his life's best performance as a young joker.
Episode III
I would say this part was the only reason for the movie's failure. People at that time were not used to see mature love story. It was the time when they were used to see Shammi Kapoor's kind of love stories with young and sweet actresses. Padmini's appearance in the last episode makes the movie relatively dull as she was not a very talented actress rather a great dancer. She was never successful in her career in Hindi movies. However Raj Kapoor acted very well in as mature joker. His philosophy extends in this one. As he shows every one is a joker in his life. Life is a stage and everyone needs to perform his part and continue with his journey.
The symbol joker was returned to him thrice as if his heart was given back. His last duologue touches the most when his says his play will not stop here this is just an interval , which may be for 15 min,15 hours or 15 months so please don't go away . He said whatever he wanted to convey from this movie . He tried to prove that from this movie joker's next phase starts and surely after that he never acted in his movies as a hero. He chose his next episode where joker was directing other jokers for his show. Certainly it is his autobiographical work. At last I must say no one can replace a director like Raj Kapoor.