Grice's squarrel Toby

When travelling to Harvard, Grice wrote in the plane, "need to postulate creature to which ascription of 'goal' makes sense". It will take him 10 more years to come up with the idea of a squarrel: Toby.

Toby, after all _wants_ nuts:

1. Toby, the squarrel has nuts in front of him.

2. The squarrel is short on squirrel-food
(observed or assumed).

3. The squarrel wants (wills, wishes, desires)
squirrel-food (By Psychological Postulate,
connecting 'wish' with intake of nuts)

4. The squarrel prehends nuts as in front
(From (1) by Psychological Postulate, if
it is assumed that 'nuts' and 'in front'
are familiar to the squarrel)

5. The squarrel joins squirrel-food with gobbling
and nuts and in front (The squirrel judges
gobbling, on nuts, in front, for squarrel-food)
(by Psychological Postulate, with the aid of
prior observation), so by Psychological Law,
from 3, 4, and 5:

________________________________________________

Ergo:

6. The squarrel gobbles, and since nuts _are_
in front of him, gobbles the nuts in front of
him.

H. P. Grice, 'Method in philosophical
psychology: from the banal to the
bizarre', Proceedings of the American
Philosophical Association, Presidential
Address, vol. 48. Repr. in his book,
_The Conception of Value_. Oxford:
Clarendon, p. 137.

I _can_ make some sense of a 'functional' ascription of a 'wish' like that. Plus, I _can_ make sense of the perceptual input that leads one to say, "I wish the cows had come home" (he is reported that the cows were all killed). But what would the behavioural output be such that ascribing the counterfactual wish (containing an 'irreal past') serve as 'explanatory bridge'? I suppose it's mere 'regret', as when I read at:

http://www.iwishihad.org/
"How many times have you said, "I wish I had?"
Your wish may be the regret that might inspire
someone else to take action, to do the right thing,
to tell someone something that would heal, encourage,
mend, create happiness, correct, overcome, soothe, etc.
Send us your "I Wish I Had" and, if it's good enough
you will receive an autographed, first edition copy of
the book."

-- I'm talking bizarrely, admittedly, but I'm hope still intelligibly.

Etc.