  `Anyone who keeps the ability to see beauty never grows old' Franz Kafka.
  In the last few years considerable progress has been achieved in our
understanding of the decays of heavy flavour hadrons. One can now calculate
inclusive transition rates in QCD proper through an expansion in inverse powers
of the heavy flavour quark mass without recourse to phenomenological
assumptions. The non-perturbative contributions are treated systematically in
this way; they are found to produce corrections of order a few percent in
beauty decays, i.e. typically somewhat smaller than the perturbative
corrections. One finds, among other things: (a) The lifetime of $B^-$ mesons is
predicted to be longer than that of $B^0$ mesons by several percent. (b) The
QCD prediction for the semileptonic branching ratio of $B$ mesons appears to
exceed present experimental values. We discuss the implications of this
discrepancy. The phenomenological engineering that has been developed for the
description of {\em exclusive} two-body modes of $B$ mesons has reached a
mature stage and awaits more precise and detailed experimental tests. First
steps towards a genuine QCD treatment of these modes are being made.
