Sometimes what children wonder can make us wonder how they wonder such interesting wonders.

Does he know that we know that he knows.
Big Billy, who had a big belly was also a big bully.
How many cuckoos could a good cook cook, if a cook could cook cuckoos.
Any noise annoys an oyster but a noisy noise annoys an oyster more
If one doctor doctors another doctor, does the doctor who doctors the doctor doctor the doctor the way the doctor he is doctoring doctors? Or does he doctor the doctor the way the doctor who doctors doctors?