On 26/7/2006 the author had some gall bladder surgery, where he was forced to undergo general anesthesia. The author carefully monitored his consciousness during the procedure, so here he is attempting to mathematically model the situation.

Assume an "event" is a point in H, or a coordinate quaternion quadruple q=(t,x,y,z), with t,x,y,z>0, similarly to how an event is modelled in physics (so a movie or regular flow of consciousness for example, would be continuous streams of quadruples q(t)=(t, x(t),y(t),z(t)), with no relativistic effects present, so time t is (for our purposes) linear. So we can assume that time and the corresponding streams of events are continuous.

The experience during the shut-down of consciousness was as follows: First, upon the
injection of the anesthetic, there was a slight disorientation, which gradually
increased. At some point, loss of consciousness occurred at t_{1}. But the
subject (the author) never "experienced" actual loss of consciousness. Instead, the
author experienced an awakening into some other forward time t_{2}, with
t_{2} = t_{1} + 3 hrs, after all the operations were completed.

Using the above notation, and if we assume that the actual moment of unconsciousness
occurs at t_{1}=1 and the moment of awaking occurs at
t_{2}=t_{1}+3, at loss of consciousness the author was located at
q(t_{1}), with:

q(t_{1})= (t_{1},x(t_{1}),y(t_{1}),z(t_{1}))
(in the anesthesiologist's room)

and suddenly the author awoke to point q(t_{2}), with:

q(t_{2})=(t_{2},x(t_{2}),y(t_{2}),z(t_{2}))
(in the anesthesiologist's room, again).

The author's position was almost identical, so we can assume that
x(t_{1})=x(t_{2}), y(t_{1})=y(t_{2}) and
z(t_{1})=z(t_{2}).

If we describe the time t of uninterrupted normal consciousness as a linear function T(t), the following graph models accurately what happens from the patient's perspective:

Time T(t) as seen by the patient

But the above function is:

T(t)={t, if t<1, t+3, if t>1}.

Converting in terms of the Heaviside step function H,

T(t) = t + 3*H(t-1)

In general, if the moment of unconsciousness occurs at t=t_{1} and if the
total unconsciousness time is t_{Tot}=t_{2}-t_{1} then the time
of the event stream as experienced from the patient who "goes under" is described by
the function:

T(t) = t + t_{Tot}*H(t-t_{1})

Some interesting facts: The patient always measures time along the y-axis. There is
a jump discontinuity at t_{1}=1, where the patient instantly jumps from time
t_{1}=1 hours to t_{2}=4 hours. The derivative of T(t) is
dT/dt=1+t_{Tot}*δ(t-t_{1}), with δ being the Dirac delta:

Rate of change of time dT/dt as seen by the patient

In other words, from the patient's perspective, time passes at a constant rate
dT/dt=1 hr/hr (for our function), except exactly at the point t_{1}=1, when
there is a *singularity*. q(t) for t_{1}≤t≤t_{2} is undefined from
the patient's perspective. This is *non-existence* for a duration of
t_{2}-t_{1} hours, so this time is actually lost to the patient, but
the patient doesn't experience it, except as an instantaneous singularity which gets
lost in the subsequent stream of events.

Now you understand why people are afraid of surgery. Not because of the
*actual* surgery (there is no pain under anesthesia), but because of their
encounter with *non-existence*. Non-existence implies *total loss of control*
and the conscious mind instinctively knows that under total loss of control there might
be *danger* for its survival, hence total anesthesia is something that the mind
instinctively avoids.