In “The Luncheon” (1981), Maugham (1874-1965) says, "But I was flattered and was too young to have learned to say no to a woman," to explain why he agreed to meet the lady despite knowing it would cost him more than he could afford. 

Inexperienced: At the time, the writer was young and inexperienced. He lived a simple life in Paris with limited money and had never thought of visiting an expensive restaurant like Foyot’s. However, when the lady praised him by writing a letter, he felt special and important.

Flattered: The lady's admiration for his writing boosted his confidence. He did not want to disappoint her by saying no. As a young man, he lacked the maturity and courage to refuse a woman's request politely. He was flattered by her interest in him. This combination of flattery and inexperience led him to agree to the luncheon, even though he knew it would drain his money.

During their luncheon, the lady repeatedly assured the writer,

I never eat more than one thing for luncheon.

In conclusion, Maugham’s statement reflects his naivety at a younger age. It shows that he recognizes his decision was not wise but was influenced by his youth and the charm of a woman’s attention.