Stressing how the way decoherence works is, to some extent, up to us, in the sense that it depends on the choice of what are the degrees of freedom that one treats as environment and which ones one treats as “the system” that should decohere. Some discussion with the audience on how much freedom one really has, or, more bluntly, on whether the whole process is “observer-dependent” and up to the conscious choice of the physicist.