  Understanding the galaxy in which we live is one of the great intellectual
challenges facing modern science. With the advent of high quality observational
data, the chemical evolution modeling of our galaxy has been the subject of
numerous studies in the last years. However, all these studies have one missing
element which is the evolution of close binaries. Reason: their evolution is
very complex and single stars only perhaps can do the job. (Un)Fortunately at
present we know that the majority of the observed stars are members of a binary
or multiple system and that certain objects can only be formed through binary
evolution. Therefore galactic studies that do not account for close binary
evolution may be far from realistic.
  Because of the large expertise developed through the years in stellar
evolution in general and binary evolution in particular at the Brussels
Astrophysical Institute, we found ourselves in a privileged position to be the
first to do chemical evolutionary simulations with the inclusion of detailed
binary evolution. The complexity of close binary evolution has kept many
astronomers from including binary stars into their studies. However, it is not
always the easiest way of living that gives you the most excitement and
satisfaction.
