A ferro cerium rod or a flint, the back of my knife, some fatwood shavings or a quick tab and I can get a flame under all but the absolute worst conditions (like low oxygen, submerged, zero gravity etc.).

Recognizing and collecting the right kind of tinder for the situation, such as it is, is another key factor in your firemaking success. If grass won't work, find and try other items that look promising. Flexibility, ingenuity, and tenacity (never give up, never surrender!!!). These are the keys to survival.