He started painting when he was 10 years old so maybe between 1916 and 1922
He did make it. It is not a painting, though, it is a lithograph.
1931
He was the best known of the surrealists.
"I am painting pictures which make me die for joy, I am creating with an absolute naturalness, without the slightest aesthetic concern, I am making things that inspire me with a profound emotion and I am trying to paint them honestly."
In December 1955, Dali gave a lecture at the Sorbonne in Paris. The lecture was titled 'Phenomenological Aspects of the Paranoiac Critical Method', and was about the morphological connections he had identified amongst cauliflowers, sunflowers, rhinoceros horns and Jan Vermeer's painting, The Lacemaker. Dali arrived at the Sorbonne in a white Rolls Royce Phantom II that belonged to his friend, the French painter Georges Mathieu. Prior to the event, Mathieu had procured 500 kg of cauliflowers from Les Halles and filled the Royce Royce with the cauliflowers to make Dali's arrival a real spectacle! After the lecture, the cauliflowers were donated to a Catholic sisterhood.
In Figueres, Barcelona, Paris, US and Figueres again.
In 1840
He contributed on Verrocchio's painting 'Baptism of Christ'. The first painting that was probably wholly by his own hand was the 'Annunciation'.
It's first painting the whole painting (or the background) in a different color, only to make the top coat colors come out better.
You might try painting it first.
He never told us.
Salvador Dali is a fantastic narrative artist. You just need to be able to look deep and broaden your thoughts to understand the meaning behind his art. Or (if this a high school art project) just make up a bunch of crap using long word that will make your teacher fall head over heels for it. :)