  The current paper is an investigation towards understanding the navigational
performance of humans on a network when the "landmark" nodes are blocked. We
observe that humans learn to cope up, despite the continued introduction of
blockages in the network. The experiment proposed involves the task of
navigating on a word network based on a puzzle called the wordmorph. We
introduce blockages in the network and report an incremental improvement in
performance with respect to time. We explain this phenomenon by analyzing the
evolution of the knowledge in the human participants of the underlying network
as more and more landmarks are removed. We hypothesize that humans learn the
bare essentials to navigate unless we introduce blockages in the network which
would whence enforce upon them the need to explore newer ways of navigating. We
draw a parallel to human problem solving and postulate that obstacles are
catalysts for humans to innovate techniques to solve a restricted variant of a
familiar problem.
