A "loner" hit his supervisor over the head with a hammer after learning his job at a Sydney insurance firm was on the line.
John Martin Chapman now spends his days playing crosswords and reading books in a park after losing his job as a computer programmer following the assault last year.
Chapman, 68, was given a suspended jail sentence on Friday after pleading guilty to wounding with intent to cause grievous bodily harm to his supervisor.
The Downing Centre District Court heard Chapman was socially isolated, had little to no contact with his family and was a "loner".
Chapman, who claimed he couldn't remember the incident at his office last year, said his job with the Insurance Australia Group in Sydney's CBD was all he had.
He conceded his behaviour at the office on January 6, 2014, was disgraceful.
"I felt very upset about it," he told the court.
"I would ask (the victim) to forgive me if he could."
The court heard Chapman's supervisor had not been satisfied with his work and he received warning if his performance didn't approve, there would be serious consequences.
After his supervisor returned from Christmas holidays, Chapman struck him in the head and shoulder with the blunt end of a hammer.
Chapman had bought the claw hammer a week before from a nearby hardware store, the court heard.
His supervisor suffered a two-centimetre laceration to his head.
Judge Chris Craigie said Chapman was one of those unfortunate people who came to a point in determining "what they are is what they do".
"When that came under threat this offender simply lacked the capacity to cope," Judge Craigie said.
Judge Craigie said Chapman was suffering from a depressive order at the time and was an alcoholic.
He sentenced Chapman to a suspended jail sentence of one year and 10 months on the condition he be on good behaviour.
