He spends a while just breathing evenly, trying to absorb the full force of the hit he's just taken, which is also a recommended procedure when you have just taken a hit.
Flowers on mouse grave in backyard, he thinks, and doesn't bother to write it on the paper, because it's not a message from the Wiser Keltham, and he doesn't even really feel that way, it's just his brain completing a cliche.