Because fire is THE most important element in practice, you must work consciously with your fieriness or lack of. It can require tremendous energy to get to a place where fire presides over your practice, where tapas leads you...
Resisting pain can frustrate you and challenge your resolve to practice and thus it is essential to see that the obstructions that appear in your path, whether physical or mental, are meant to be there for your learning and growth.
Stepping on your mat each day is walking into the forest, practice is sitting down in the middle of that scary place and undertaking to meet the source within...