  We discuss few, apparently different, but actually tightly related problems:
a)Strangeness in the nucleon; b) B --> eta' decays; c)Intrinsic charm in the
proton spin problem. We argue that all these problems have a common origin and
related to the OZI rule violation in 0^{\pm} vacuum channels . It leads to a
noticeable role of a nonvalence component with 0^{\pm} quantum numbers in a
hadron.}
