I had a business colleague who was based elsewhere in Asia for several years. He visited Thailand every few weeks the entire stay. When he returned to the US,

I had a business colleague who was based elsewhere in Asia for several years. He visited Thailand every few weeks the entire stay. When he returned to the US, immigration gave him the same rundown. When he finally convinced them that he was just a young guy who wanted to have fun, they waved him through with a smile.