It's all the same to him!
Driving to my friend's yarn shop the other day, I was having a conversation with my son (age 5) about his bathtime. He decided that he wanted to take a shower, but with only water -- no soap. I explained that he HAS to use soap, because it's the soap that gets him clean. We moved on to some other equally interesting topic and I didn't think another thing about it.
We got to my friend's shop and visited for a while, and then Noah excused himself to use the restroom. He was in there much longer than I felt he should be, so I went to check on him. He was standing at the sink with soap all over his hands.
"Noah, what are you doing?" (Ok... I know I just told you I had witnessed what he was doing, but it's an obligatory question...LOL)
"I'm washing my hands."
"Well you've been in here long enough... come on now, rinse off." I turned the water on so he could rinse his hands.
"But MOM... you said it's the SOAP that cleans you."
I just shook my head. "You are so literal," I said.
"Well I'm only five. Of COURSE I'm little!" He was fairly exasperated with me, I know. I just shook my head and went back into the other room. Gotta love that literal little man.