  I address the question of measuring the subjective perception of the passage
of time at the individual level in relation to its objective duration using a
physicist-type treatment. A simple model is thus built in terms of a very small
number of equations, which is found to yield a quantitative framework for
individual subjective perception of time. Given an objective unit of time like
the year, the hypothesis is to introduce a subjective unit of time for each
person, which is inversely proportional to the number of objective units
already experienced by that person. A power law is also considered. The model
is then implemented by stacking individual clocks, each being linked to social
rituals, which mark and shape the specific time of an individual throughout
their life. For each person, the first of these events is their own birth. A
future horizon, as well as an origin of the past, are then defined, along with
a speed of subjective passage of time. The model shows that the price for the
first ritualized socialization is to exit eternity in terms of a future to be
lived with the simultaneous reward of experiencing a moment of infinity
analogous to that of birth. The results recover common feelings about the
passage of time over a lifetime. In particular, the fact that time passes more
quickly with age.
