Common sense tells us that people are changing their minds all the time. Also, the environment is changing as time goes by. Mathematically, these issues will lead to some time-inconsistency in optimal control problems. In this talk, we will present a general framework on time-inconsist
optimal control problems. It is shown by some simple examples that naive optimal controls are not time-consistent. Using some sophisticated approach by means of hierarchical differential games, one can obtain time-consistent solutions to the time-inconsistent problems.