Henry Cobb wrote:

If it was all in his head, then he was going around and saying some VERY
strange things all that time.

What's the reaction of everybody else to this, from the start?

While the story leaves this ultimately up to the readers' imaginations,
my answer would be that the process took place in stages:

<Stages snipped>

Heh.  This sounds rather similar to the premise of another fanfic I read.  It was a 
very very good fanfic, and one I enjoyed immensely.

I wonder.  Has anyone here actually read "Urusei Yatsura: 'Just Another 
Dream'"?

I won't spoil it by giving away the plot, suffice to say that it does involve 
the normal UY storyline being only in Ataru's (and in this case, Lum's) dreams.
 
Ciao,
                               Terence Fergusson
                            -- Student of Advanced Murphodynamics
                            -- Stranded in an Anime-free College

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"Right, you old letch!  You asked for it!  HAPPOSAI
TENKETSU!"
"What?  Huh....  what are you.... no!  NO!  *splut*"
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