The 24-year-old five-time Olympic champion stunned world swimming in November when he announced his decision to quit the sport just months before the world championships and less than two years ahead of the 2008 Olympics in Beijing.
"The full stop was put on me coming back to swimming the day I announced the end of my competitive swimming career, it's as simple as that," Thorpe told reporters in Melbourne on Friday.
"I've thought about swimming, but it's not about racing against anyone else.
"Now when I think about competitive swimming, it's a memory, rather than a thought of what I might be able to do at the next competition."
Thorpe was attending the start of construction of the temporary swimming pool at the Rod Laver Arena to be used for the world championships from March 17.
But the Australian, an 11-time world champion, including six titles at the 2001 championships in Fukuoka, Japan, said he was happy he had made the right decision.
"Now's the time for me to adjust into a new career, whatever that might be, and just preparing myself for that.
"It will take a high focus in television this year and I will probably have parallel careers in other areas as well."
Organisers said they planned to include a tribute to Thorpe in the opening ceremony to the March 17-April 1 championships.