One comment on the video The USA is a "Third World" Country for Millions of Americans by the YT channel Raising Wildflowers (60.4K subscribers) had a quote by George Carlin. I asked GPT for sources to check its veracity. I edited it a bit and checked the links.
In his HBO comedy special Life Is Worth Losing (2005), in the bit about the American Dream, George Carlin quips:
“That’s why they call it the American Dream, because you have to be asleep to believe it.” Goodreads
This line has frequently been quoted as:
“It’s called the American Dream, 'cause you have to be asleep to believe it.”
TIME magazine included it in a list of Carlin's top quotes, affirming its authenticity. Time Goodreads and other quote databases also attribute it to Carlin. Goodreads
In context, Carlin was critiquing the notion that the so-called "American Dream" is largely a manufactured illusion—and that people who believe in it may not fully grasp its reality until it's too late.
So yes—this pithy line really is Carlin’s, often shared because of its punchy nihilism and social commentary.