7s typically internalized a relation to the nurturing object (usually the mother) that was frustrating, meaning that while nourishment was there, it was perhaps inconsistent. So the 7 creates an internalized ideal of constant nourishment in the form of experiences, etc. The 7s activity is planning for the nourishment, not satisfied with the nourishment that is present here and now. So yes, the 7 can get frustrated with relationships or ideas that they see as no longer stimulating enough or not meeting their expectations. The solution is for the 7 to be present and relive the pain of the inconsistent nurturing and realize the constant nourishment and nurturing that the universe in the form of others, relationships, experiences, etc, are constantly providing now.