The arrow was the last one in his quiver. He'd left it alone for a few weeks, not finding a trader or deserted campsite to barter or salvage one. So he made do with his knives.
But then he came to a clearing, and the most beautiful deer he'd ever seen stood there. The price he would get for the pelt was worth it. So he took the arrow, aimed, fired.
It went wide, and vanished into the bushes. And while he lost the deer, having to kill an angry bear with just knives was a good story to tell.