Unintended consequences

Julian had one usable "sippy cup"-- the kind that really cannot be spilled. It is an engineering marvel. Of course, having only one cup poses a bit of a logistical problem, since we end up using it all the time. This prompted us to buy a new sippy cup of a slightly different design (since our main cup is longer made. Now Julian will only drink out of his new cup. We are right back where we started.