Daniel Richard Marsh (25) was spotted by eagle-eyed officers outside the BP Ascot in the early hours of August 15.
He and an associate had donned black rubber gloves and had their hoods up, and when questioned, Marsh was found to have two knives in a sheath attached to his belt.
The defendant had been in custody since September, the Dunedin District Court heard last week, and had done previous stints behind bars.
Marsh had been assessed as having limited cognitive ability and struggled with consequential thinking, Judge Dominic Flatley said.
The defendant, he said, had a genuine desire to end the cycle of offending and imprisonment.
"You need assistance," the judge said.
Marsh pleaded guilty to possessing a knife and preparing to commit an offence, and the court heard his night of crime started an hour before the petrol station incident.
He approached a man standing outside a bowling club who told him he was waiting for a taxi.
Marsh responded by moving towards the victim and lifting his shirt to reveal a large hunting knife and a steak knife.
The defendant suggested he would get in the taxi when it arrived and reached for the weapons.
When the victim’s friends arrived, Marsh left the scene.
Police arrested the defendant in Tay St, outside BP, shortly afterwards and he was "unco-operative", the court heard.
Marsh said the knives were "for his own protection" and he argued he was allowed to carry them around in public.
Judge Flatley noted Marsh had another weapons conviction last year and was convicted of being unlawfully in a building in 2018.
Marsh was sentenced to 15 months’ intensive supervision, which included the condition that he only live at an address approved by Probation.
For greater oversight, the judge also imposed judicial monitoring, which meant he would receive three-monthly reports on the defendant’s progress.
