In Ancient Greece, victorious athletes were presented with laurel wreaths to wear. They were, and still are, signs of great accomplishment, unless you start resting on them
To ‘rest on your laurels’ means that you get lazy or complacent about what you could achieve because you’re too busy basking in the memories of former glories. It’s a phrase that continues to have significant relevance in the world of sport (‘Yeah, you may have won the World Cup but don’t rest on your laurels!’), which is also where it originated.
Winning competitors in the Ancient Greek Phythian Games, a forerunner of the Olympics founded roughly in the 6th century BC, were given wreaths made of the aromatic laurel leaves as a symbol of their triumph. It was believed that the god Apollo declared the laurel plant sacred after his true love – the nymph Daphne – was turned into one. That is why Apollo was depicted wearing a crown of laurel. As the Phythian Games honoured Apollo, a laurel wreath was the appropriate prize for a victor, or ‘laureate’.
The Romans borrowed the idea and began presenting laurel wreaths to victorious military commanders. But there was no implication that ‘resting’ on them was bad. Roman generals could spend the rest of their careers savouring their past successes. The negative connotation, and the saying, only came about millennia after the decline of the Ancient Greek and Roman empires.
A ‘laureate’ is still an esteemed title today, with recipients of the Nobel Prize being referred to as Nobel Laureates. Via Why we say: ‘resting on your laurels’