It is true that Plato and Socrates did not create works with titles like "Maximizing Happiness in Your Life."
But they did address the subject of happiness in their philosophy. So did many other philosophers through the years, a fact capitalized upon by modern philosopher Frederic Lenoir.
He culls the ranks of philosophers past and present for the material in his book, Happiness: A Philosopher's Guide. Frederic Lenoir visited in 2015, and we revisit the interview here.