Originally Posted by Moridin
He didn't quit being IM. At all. The very last thing he says before the credits is "I am Iron Man".
The last thing he did
was destroy the suits and walk off into the sunset. Tony without the suit is not Iron Man. He can't shoot repulsors, fly, fire missiles, fight Thor or do any Iron Man stuff as Tony Stark. He can say whatever the hell he wants but without the suit he's not Iron Man