His kit is small, and while I wouldn't call anything useless, I don't really see a need for a sewing kit or a scalpel for that matter. If I'm going to include a knife in my PSK, it will be one that has a positive grip, so I don't cut myself when wet and cold. Anyhow, for a PSK, life-saving first aid, signalling, fire, and staying dry take precedence over any knife. Remember that most survival situations are 3-5 day waiting games, not wilderness expeditions. The idea should simply be to sit tight, stay warm and try not go nuts, while awaiting rescue. Save the hiking, fishing, rabbit hunting, navigating, and river crossing supplies for the wilderness expedition pack. A PSK should only be designed to get you back to civilization alive when an unanticipated survival situation arises. If it is bigger than just that, it might be left behind.
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The Bell Curve says ignorance is normal.