Andrew Merritt, 34, asked the 88-year-old victim if he could spare a couple of pounds and the kind pensioner took out his wallet and gave him £3.10.
CCTV showed Merritt hugging the elderly man before grabbing his wallet and walking away smiling.
As the elderly man pleaded for it back, Merritt counted the large wad of £20 banknotes from inside the wallet.
He then kept the cash and dumped the wallet nearby.
Nottingham Crown Court heard Merritt stole £1,100 in the robbery which happened in Potter Street, Worksop, Notts., on August 1 this year.
Witnesses went to the elderly man’s aid before calling the police.
Footage shows Merritt stopping in a doorway of a house where he changed his T-shirt in a bid to avoid detection.
Merritt was arrested after a police officer recognised him from the CCTV footage.
Bodycam footage shows Merritt being arrested as he lay on his bed six days after the robbery.
During a police interview, Merritt denied stealing the money, insisting the elderly man had agreed to purchase a bike from him.
Merritt, of Cheapside, Worksop, later admitted robbery and today (Wed) he was jailed for four years at Nottingham Crown Court.
He was also given a Criminal Behaviour Order banning him from Workshop town centre for four years and ordered to pay a £228 victim surcharge.
The court heard he has previous convictions relating to 118 offences, including theft, shoplifting, assault, breaching court orders and burglaries.
Following the sentencing, Detective Chief Inspector Nick Hall, of Nottinghamshire Police, said: “Merritt’s actions were cowardly in the extreme.
“He preyed on a vulnerable man knowing he would not be able to stop him making off with his money.
“When he asked for £2, the elderly victim gave him that and more, out of the goodness of his heart.
“It was a kind act of generosity and so it was staggering that Merritt repaid the gentleman’s empathy by robbing him of such a vast amount of money.
“It was an extremely cruel crime and I am pleased Merritt has been made to pay for his appalling actions.
“I hope the outcome at court provides the victim with some comfort in knowing that Merritt can no longer harm anybody in our communities.
“I’d also like to thank the witnesses who came forward with information so that we could put Merritt behind bars.”
