It might also depend what part of Thailand you're in. Maybe it's more normal in Isan. Here in rural Lower-north, people are very conservative, and being drunk is frowned upon and done behind closed doors. Most people I see just bring a bottle of whiskey to a picnic and listen to some music, they aren't yelling and yahooing. They are mindful that being publicly drunk is taboo.
In addition to that it might depends on the backgrounds of you and the people around you. I come from a working class background and where I come from not getting drunk regularly is a bit unusual. And in Thailand I'm surrounded by middle and upper class Thais who like to drink but consider drunkenness taboo. If you come from a middle class background and are hanging around working class Thais you might have the opposite experience.
Thailand's relationship with alcohol is complicated. The laws are extremely strict, but not very enforced. There are so many public holidays where you can't buy alcohol, hours are heavily restricted. On the other hand you can buy alcohol in a convenience store, which is illegal where I come from.