In Thailand, traditionally, hard liquors are more popular than beer and wine. People get together to drink and eat at a restaurant and then just continue to sit and talk and drink long past dinner. Since drinking reduces the sensitivity of the taste buds, people ask for spicier food as the evening progresses, so the cooks pile on chili peppers and seasonings to please the crowd.
Pad Kee Mao has changed quite a bit in Thailand. Some people now make it with vegetables. Some recipes confused Pad Kee Mao with Pad Cha which starts the same as Pad Kee Mao with garlic and chili peppers but ends up with Chinese keys, green peppercorns, kaffir lime leaves and Thai basil. This Kee Mao recipe keeps the authentic flavors and ingredients with the right amount of heat.