Shoulder planes and rabbet/rebate planes have irons which extend just outside the body of the plane - on both sides. And what extends outside the body of the plane also has a nice square corner.
Now even the Veritas shoulder planes lack a real - be able to grab it - handle so the gripping position other than the Push It mode can be "adaptive" - figure out some way to hold this thing where you want it - then pull or push it - somehow.
And it doesn't take long to forget that these planes have that little bit of sharp edge - and that nice sharp corner - waiting to bite you as you try and find a grip for some weird planing need. Because the edge and corner are so sharp, I only realize I've managed to once again slice my finger - when the blood stains on the wood become noticable. The slice is never deep - just deep enough to a) draw blood and b)be irritating for a day or two.
During those few Did It Again sensativity periods I get real careful of my grip. But somehow, once the "reminder" goes away - I forget
- and often Do It Again.
Have you got a tool that bites you on a regular basis - not hard or deep - but enough to be annoying - for a few days?