Growing Wacky Weeds

So my Granny used to tell me "you're growing like a weed." That must've been well before I hit my stellar height of 5' 2''. I must've been quite the weed before then. Our kids also are growing like weeds emotionally, socially, physically, spiritually, cognitively, etc. They excel at such things. They also excel at screaming, throwing fits, and disobedience. Oh well, not much unlike me. The ebb and flo of disobedience/obedience in our home is enough to drive anyone insane, especially this Mommy. And every day is different. What works one day all of sudden doesn't work the next. I have likened my little guy to Jekyl/Hyde, also hearing other Moms call their kids the same thing--never to their face, mind you! But we chuckle and cringe at the same time because that is what we face every day with them. The point of this rattling of mine is to put a theory out there that I've heard from two Moms recently. Kyle has had one of those weeks of lots of defiance, pushing every single boundary, being plain difficult over the smallest things, and challenging us at every level. Two Moms recently said to me, regarding their own kids, that they have noticed behavioral changes in their kids right before the child hit a "new level" in their development. They were disobedient more or more clingy or just something was 'off.' They then saw the child reach some new milestone. I am wondering what others think. I've never heard this or read about this in any parenting magazine but I'm curious what others think of this theory or if you've experienced similar patterns. I have in mind what I personally hope is Kyle's next milestone, but who knows, maybe it's just Kyle being three. Do their little bodies know something is changing inside or even outside? Are they wanting to do something new but are experiencing a range of emotions but can't label them, therefore the acting out or clinging? Blog back and let me know! Inquiring minds want to know...