It’s a scientific fact:*
A three-year-old playing by himself can methodically work through the most intricate toys and attempt the most gravity-defying physical feats if he is in his room pretending to nap during quiet time.
Yet he cannot manage more than three minutes by himself without apocalyptic levels of crying and frustration if you are in the shower.
* (in our house. your results may vary.)
NaptimeWriting 
Other scientific facts…
Three-year-old female could care less about anything said when addressed directly.
Three-year-old female trows fits of epic proportion when something is said to someone else on the phone.
Oh, nap, you are so right! How astute and hilarious!
And ck, too! Sometimes it seems like the only time my kids want to talk to me is when I pick up the phone…
LOL
I can’t think of anything as clever as ck.