Actually, when the article says: > people who are chronically sleep deprived, like people who've had too much to drink, often have no sense of their limitation

Actually, when the article says: > people who are chronically sleep deprived, like people who've had too much to drink, often have no sense of their limitations. What it means is that people don't realize the degree to which they are being inhibited (although the studies did not test this, this is based on one piece of anecdote.) The article is not saying that people think that their limitations are greater than they otherwise would, as is the case with alcohol or testosterone.