This is the story of Sidharth Mehra (Ranbir Kapoor), a lazy, unmotivated slacker from Mumbai whose life undergoes a series of changes after taking his final year college exams. Sid's world is breezy, carefree, and without any true responsibilities. The most important elements in his life are his friends, his camera, his car, and his X-box 360.

Sid thrives around his two best friends, Rishi (Namit Das) and Laxmi (Shikha Talsania), very rarely communicates with his mother Sarita (Supriya Pathak) and takes his father Ram Mehra (Anupam Kher), and all his hard earned wealth for granted. Despite all these traits, Sid is an honest boy; sweet, funny, and above all, a good friend. Aisha Bannerjee (Konkona Sen Sharma), an aspiring writer from Calcutta, learns this soon enough when her path crosses with Sid's on her first day in Bombay, Ambitious, well-read, and driven, Aisha has come to Bombay to realize her dreams as a writer. Despite their contrasting personalities. Sid becomes Aisha's first friend in the city.

As Aisha sets up her life in Bombay, with the help of Sid and his gang, Sid allows for time to fly by over long drives, parties that stretch well into dawn, and endless hours doing absolutely nothing.
But summers vary rarely dull these days and Sid's summer is no different. A series of circumstances and events compel him to take stock of his life and take a hard look at himself. Will he, at some point figure out what he's supposed to be doing with his life?

Review as per NDTV

Wake Up Sid is the coming-of-age story of a slacker named Sid, played by Ranbir Kapoor. In a wonderfully done title sequence, debutant director Ayan Mukherji shows us Sid struggling with accounting the night before his final exam. He’s had four cups of coffee and stays up till 3 am but he doesn’t get past the first question.

Unfortunately the film doesn’t maintain this crackling momentum and becomes a patchy, predictable story held together by the sheer prowess of Ranbir. Ayan, working from his own story and screenplay, skillfully creates Sid’s state of arrested development.

This is the kind of collegiate who sleeps in Sponge Bob sheets, doesn’t last one week in his father’s bathroom furnishing business, which he describes as full-on pakao, and has no ambition or plans for the future apart from getting drunk. Sid meets Aeysha, played by Konkona Sen Sharma, a slightly older, more mature and focused girl, who moves to Mumbai from Kolkatta to create an independent life for herself.

The two, polar opposites, become friends though she’s quick to explain that he is not her type. She is looking for a man, not a boy. Eventually, Aeysha helps Sid grow up. He discovers that life is a little more complicated than the comic books he reads. Wake Up Sid has honesty and freshness. Ayan creates some genuinely tender and moving moments.

There is a lovely little scene in which Sid makes an impromptu cake for Aeysha’s birthday. And Sid’s confrontation with his parents packs a wallop. However, Ayan isn’t as successful at stringing together the moments.

The pacing in the first half is very slow. Towards interval, the film gathers an emotional momentum but afterward it becomes slack again. The bigger problem is that the crisis of the characters never feels sufficiently awful or urgent.

This is a Karan Johar production so reality is severely air-brushed. Nothing really bad ever happens to Sid or Ayesha. Within days of arrival she finds a lovely, airy, affordable flat and a job at the city’s hippest magazine, Mumbai Beat. Within months, the magazine’s super-cool editor is dating her and she has her own column.

Sid doesn’t get too sweaty either. He gets an internship at the same magazine, which becomes a job as assistant photographer. After one dressing-down from Ayesha, he also starts to clean the house, do the dishes and even wash the dirty laundry by hand. It’s all so quick and convenient that Sid’s struggle to find his voice and identity seems half-baked.

We never feel that anything is really at stake here. Konkona also presents a conundrum. The makers obviously cast her because she isn’t the standard-issue mainstream heroine but they don’t want her to be too plain either. So she is regular working girl wearing artfully applied pink lipstick and Manish Malhotra casuals. Her character seems like a Kjo version of the more hard-edged Sona in Luck by Chance. Konkona and Ranbir have a nice chemistry as friends but aren’t entirely convincing as lovers.

Wake Up Sid belongs to Ranbir. The actor is pitch perfect as the dazed and confused Sid. He manages to be infuriating, infantile and loveable in the same moment. We root for him from the minute we see his comic-book socks.

Finally then, Wake Up Sid can’t match Dil Chahta Hai, which even eight years later remains Bollywood’s gold standard for coming-of-age movies. I’m going with a generous three stars and recommending Wake Up Sid with reservations.