You ended up pointing out an excellent reason for why it's a smart idea to comment on what pieces of your code do....
New functions are added all the time that replace the old way of doing things. Documentation gives the creator a clue to what all those lines actually do years later, after they've gotten into the habit of using new functions like llSetAnimationOverride, llSetRegionPos, llGetObjectDetails(agentKey, OBJECT_BODY_SHAPE_TYPE), and llSetPrimitiveParamsFast to replace blocks of obsolete code, timers, and outdated user created functions they may have included in their code years ago.
Our writing style changes too, depending on mood, circumstances, and time...whether it's writing a term paper, or recreating a board game in LSL. Hammering out 6 of 12 pages of a history paper the night before it's due is going to have an effect on recall when we reread it a month or a couple of years later. The same is going to happen during a crazed self-imposed deadline in getting a complex script to do what we need it to do. That "oh, yeah...that was pretty cool, I forgot I did that" or "what was I thinking" reaction. Documentation does a pretty good job of walking us through the fog.