Since I have seen no reply to what the humor is to Minnesotans in "you bet":
 
In Minnesotan speak "you bet" is a general purpose answer to any question, which may -
or may not - signify agreement it also can be used as punctuation, much like "eh" north
of the border.  It was funny because of the time he spent in Russia but still speaks
Minnesotan.  It would be as if a Canadian in Atlanta said "I'll have me
some of them grits, eh"
 
Like Dick Cavett, the humor is more understandable if you are a Minnesotan but hard to
explain if you are not.
 
me
 
 
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mark e. gibbons         [log in to unmask]          Kennedy Space Center
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                                                - Montgomery Burns -