Florence,
I don't know why you think they mean the opposite. They seem to have similar meanings to me.
Here a few examples from the internet.
There are a lot of things that are coming up this month. So many things I just recently placed them all into my calendar. But it’s good to stay busy with positive things. So here it is the upcoming schedule:
July 11: FilAmFest’s Community Clean-Up.
July 12: Philippine Independence Day Festival.
July 23-26: San Diego’s 40th Comic-Con!
July 25: Asian Heritage Awards.
I know that’s a lot for one month. On top of that, I’ll be leaving for week of vacation at Walt Disney World! I COULDN'T ASK FOR ANYTHING LESS. I feel as though I’m finally doing something important.
A busy and important vacation was exactly what she wanted. She wouldn’t have been happy with less.
She couldn't ask for less, i.e., she received exactly what she would have asked for.
Compare this....
Now, about the photography… like I said before, I really liked it and I COULDN'T EXPECT ANYTHING LESS, since it was directed by Masakazu Ato, the same cinematographer that directed Kokuhaku. What I liked the most about it was the wide points of view.
She couldn't expect anything less than excellent photography, because that is what he always produces.
She couldn't expect less, i. e., she received exactly what she would have expected.
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Both expressions could have negative meanings as well.
The kids are great sometimes a little unruly but hey I COULDN’T ASK FOR ANTHING LESS...How are things in your new home town?
Your inability to read and your condescension are astonishing. I COULDN’T EXPECT ANYTHING LESS from a liar who claims to be a Republican but will ONLY attack conservatives. PLEASE show me where "I agreed with her" and said that the Queen is "the chief decision maker