Don is a single twentysomething who constantly fails to guide his way through life. His overactive mind doesn't help things as it plays out scenes of what he shouldn't say or do. When he moves into his recently deceased grandmother's house, he meets Eddie: his Gran's carer who doesn't want to leave. To help pay his rent, he decides to get a roommate in the shape of his teenage sweetheart...
With Abby having been gone for about six months, Don and Eddie both want different women to move into the spare room.
Don starts dating an older woman but can't handle the grown up world she lives in. Sam has befriended a male friend from university who Don catches rifling through her underwear drawer.
Sam is dating cool singer-songwriter Jackson, reawakening Don's hitherto unspoken ambition to be a musician.
Don's lodger, Sam, invites her brother, Jamie, over for the weekend. Dan starts to wonder if he is gay.
Don joins a gym to prove to Sam and Eddie that he's fit and healthy, but he fails to get beyond the running machine without passing out. He soon gives up on the gym and decides to go for a colonic irrigation, instead, where he ends up agreeing to go on a date with the therapist.