  We summarize the results of a 20-year campaign to study the light curves of
BK Lyncis, a nova-like star strangely located below the 2-3 hour orbital period
gap in the family of cataclysmic variables. Two apparent "superhumps" dominate
the nightly light curves - with periods 4.6% longer, and 3.0% shorter, than
P_orb. The first appears to be associated with the star's brighter states
(V~14), while the second appears to be present throughout and becomes very
dominant in the low state (V~15.7).
  Starting in the year 2005, the star's light curve became indistinguishable
from that of a dwarf nova - in particular, that of the ER UMa subclass.
Reviewing all the star's oddities, we speculate: (a) BK Lyn is the remnant of
the probable nova on 30 December 101, and (b) it has been fading ever since,
but has taken ~2000 years for the accretion rate to drop sufficiently to permit
dwarf-nova eruptions. If such behavior is common, it can explain other puzzles
of CV evolution. One: why the ER UMa class even exists (because all members can
be remnants of recent novae). Two: why ER UMa stars and short-period novalikes
are rare (because their lifetimes, which are essentially cooling times, are
short). Three: why short-period novae all decline to luminosity states far
above their true quiescence (because they're just getting started in their
postnova cooling). Four: why the orbital periods, accretion rates, and
white-dwarf temperatures of short-period CVs are somewhat too large to arise
purely from the effects of gravitational radiation (because the unexpectedly
long interval of enhanced postnova brightness boosts the mean mass-transfer
rate). These are substantial rewards in return for one investment of
hypothesis: that the second parameter in CV evolution, besides P_orb, is time
since the last classical-nova eruption.
