Frank Abagnale has a ton of nice moments (that show he has balls of rock), but the best one is when Agent Hanratty walks into the hotel room that Frank's been using to forge cheques with gun out, Frank steps out of the bathroom, never misses a beat in pretending to be a Secret Service agent and then, once the FBI agent has lowered his gun... asks to see some ID. Balls of rock? Fuck it, he's got balls of titanium.
Far more incredibly, the entire movie is based off a true story. It is basically a Crowning Life of Awesome. This troper heartily recommends the book on which the movie is based.
How did Abagnale fake his way into practicing law in Louisiana? Simple: he studied for the bar exam, took the test three times, and passed it on the third try. For once in his life, Frank Abagnale "faked it" by actually becoming a licensed attorney.
After Frank Jr. moves to a new school, he pretends to be a substitute teacher to get back at a bully. He does this successfully for a week.
Frank manages to outfox the FBI with nothing but a suit, an empty wallet, some food labels, and a decoy.
The fact that after being convicted, his expertise got him a responsible job in the FBI, and when he was through with that, he became a millionaire legitimately - and paid back every dime he stole.
In an 'interview' with the FBI where Hanratty is trying to persuade his boss to hire Frank, Frank only has to pick up a cheque to tell it's fake (amazing the boss), noting that the paper is too thick and flexes wrong, and then adds thats the ink smells wrong and is too heavy to confirm his analysis.
While these are subtle things that Frank likely picked up because his father owned a stationery store, his first clue was something obvious that most people would easily overlook - if this was a real check, why is there no perforated edge?
One of Frank's best moments in the movie is when he isn't even present. Hanratty and his FBI agents are swarming a car outside Miami International Airport, only to find a frightened driver paid to wear a pilot's uniform and pick up a passenger. When they ask him who he was receiving, the driver pulls out a sign reading "Handratty" [sic]. Cue Carl looking up and seeing a single Pan Am plane taking off.