Read these excerpts from The Strange Case of Dr. Jekyll and Mr. Hyde. Excerpt 1:

I had but to drink the cup, to doff at once the body of the noted professor, and to assume, like a thick cloak, that of Edward Hyde. I smiled at the notion;
it seemed to me at the time to be humourous; and I made my preparations with the most studious care.

Excerpt 2:

Now, however, and in the light of that morning's accident, I was led to remark that whereas, in the beginning, the difficulty had been to throw off the body of Jekyll, it had of late gradually but decidedly transferred itself to the other side. All things therefore seemed to point to this; that I was slowly losing hold of my original and better self, and becoming slowly incorporated with my second and worse.

In excerpt 1 Dr. Jekyll is amused; in excerpt 2 Dr. Jekyll is

excited.
-concerned.
apologetic.
embarrassed.