  The shear-thickening behaviour of wormlike micelles, at concentrations just
below overlap, remains unexplained. In some cases it has recently been
confirmed that very slow relaxations must be present even in the quiescent
state -- for example, the shear thickening properties can depend on earlier
thermal cycling. We present a speculative scenario based on the presence, just
below the (apparent) overlap threshold, of large rings whose linking and
delinking kinetics control the shear thickening process. Equilibration between
rings and open chains in turn controls the slow relaxations.
