I think he is speaking of people/ friends/ lovers who aspire to join the circles of people/ things they admire. The people they want to join he sees as fads. Fads are dangerous and end up hurting you, because they don't last forever. This song assumes he isn't phased by these fads and is only interested in who his friend/ lover/ person is as an individual. When they return off their little fad, the blindfold (curtain) it caused them to have (and blocked him out) will be lifted and they will once more enjoy each others company.
I think he is speaking of people/ friends/ lovers who aspire to join the circles of people/ things they admire. The people they want to join he sees as fads. Fads are dangerous and end up hurting you, because they don't last forever. This song assumes he isn't phased by these fads and is only interested in who his friend/ lover/ person is as an individual. When they return off their little fad, the blindfold (curtain) it caused them to have (and blocked him out) will be lifted and they will once more enjoy each others company.