The Spain international signed an 18-month loan deal with his boyhood club from Milan on Monday, returning to the Vicente Calderon after seven years away.
Torres' move follows a difficult spell for the striker, who failed to discover his best form during three-and-a-half years at Chelsea before another six months of struggle on loan at Milan, who signed the 30-year-old permanently on Saturday and are thought to be close to sealing the signing of Atletico's Alessio Cerci as a makeweight in the deal.
But the former Calderon captain hopes the switch to Atleti will help him enjoy his football once again.
"I'm going to Atletico in search of happiness," Torres said. "As a child my dream was to play for Atletico, and to return is another dream come true.
"[The fans] know it's my home and know that I have felt the sadness of their defeats the joy of their triumphs.
"I have jumped off the couch at their successes and nobody can doubt how I will feel when I pull on that shirt again.
"The Atleti fans always ask that you leave everything on the field and I assure you I will give all that and more."
Torres will join Atleti on January 5, subject to a medical.
