  We argue that a large fraction of the proton spin comes from a contribution
due to a nonperturbative intrinsic charm component of the proton. An account of
this contribution removes an apparent contradiction between the data and exact
K\"{u}hn-Zakharov low energy theorem. On the other hand, we show that a large
intrinsic charm spin component of the proton is implied by recent CLEO data on
B -> \eta' decays. We argue that the proton spin and B -> \eta' data are
manifestations of the same physics with full agreement between two different
estimates of the intrinsic charm component of the proton spin. Our results
suggest an explanation of the polarized DIS data and have profound consequences
for future experiments on charm production off a polarized proton. A
microscopic origin of the effect is related to strong well-localized gluon
fluctuations (instantons) where the mass of the charmed quark is not a
suppression factor at all, as was naively expected earlier.
