The Weirdness Chronicles: Spring Leaf Tear

I've spent a decent amount of time this spring pulling what I think of as "dead leaf collars" off of spring bulb foliage.  You know how the green spears of foliage come up and pierce through leaves, only to get choked and strangled by the wiry veins on those same leaves when they get larger?  That's what I mean.

I assumed that this piercing only happened to the brittle inside parts of dead/decaying leaves.  But then I discovered this:

 

I barely understand why the dead leaves get pierced (I always kind of assumed that they were somehow impaled upon the young foliage via the wind we get so regularly here) but I definitely do not get how a thick, healthy heuchera leaf falls prey to the pointy tip of tulip foliage.  Heuchera leaves are on fairly bendy stems... why wouldn't the tulip foliage just push it off to the side, if anything, as it sprouts and grows?

I confess, I do not get this at all.  What in the world is going on here?  Do any of my more scientific-minded friends have any good answers for me?  The question of "Why," is driving me a little crazy on this beautiful spring day!