Agatha maintained that she had a happy childhood. Her mother, a good storyteller, did not want her to learn how to read until she was 8 years old. However, a determined Agatha taught herself how to read, and was soon devouring chapter books. Mrs. Molesworth's The Adventures of Herr Baby was one of her favourites. Edith Nesbit's The Phoenix and the Carpet and The Railway Children helped to expand her imagination. Agatha also enjoyed Sir Arthur Conan Doyle's Sherlock Holmes, sewing the seeds of a detective novelist.
Agatha started her writing career with short stories, penning the title The House of Bravery. Her later short stories, reflecting how well read she was as a child, were based on nursery rhyme titles:
And Then There were None (Ten Little Indians); One Two Buckle My Shoe; Five Little Pigs (This Little Piggy); Crooked House (There Was a Crooked Man); A Pocket Full of Rye (Sing a Song of Sixpence); Hickory Dickory Dock; and Three Blind Mice. (https://en.wikipedia.org/wiki/Agatha_Christie)
Her first novel, Snow Upon the Desert, featured scenes from Cairo, Egypt which she had visited. Rejected by six publishers, it took Agatha five years to publish it.
The Mysterious Affair at Styles, featuring the Belgian detective Hercule Poirot, was Agatha's first detective novel. Poirot, who would become famous, was based on the Belgian refugees who appeared in her town after the First World War. Agatha continued to write detective stories, often inspired by real life events. In 1934, a train trip to Istanbul led to her novel Murder on the Orient Express, one of her most famous title which was later made into a film.
In 1928, Agatha divorced her first husband, Christie, and married archaeologist Sir Max Mallowan. She often joined him at excavations sites. While he dug, she would clean off artifacts, reconstruct pottery, take photographs and record field notes. These came in handy for future detective novels like: Murder in Mesopotamia (1936), Death on the Nile (1937) and They Came to Baghdad (1951).
In total Agatha penned over 60 detective novels, making her the best selling fiction writer of all time, save maybe Shakespeare. The young girl who had been inspired by Sir Conan Doyle went on to inspire other generations to read: "The gripping whodunits of Christie turned people into voracious readers." (http://www.indiatvnews.com/buzz/life/agatha-christie-murder-mysteries-235.html)