fall philosophy

With these beautiful fall days we've been outside trying to take in the leaves while they're still around, and generally enjoy the last warm days of the year. As the kids are tromping along and playing they usually comment about the trees and pretty much anything they see-its constant stream of consciousness with toddlers! And now that Gemma's old enough she's started asking the great "why?" to about anything and everything. 

For instance; "Why do they leaves turn yellow and have to fall off Mama?"

This question has me somewhat stumped as to how to answer.

"Because this is how nature works; things grow and then they die."

That seems a little dark for toddler philosophy doesn't it? 

Or how bout: "Just as we die and then experience the Resurrection and new life of Christ so too must the leaves turn yellow, fall off, and die so that they may live anew next spring!" 

Holy theology lecture batman! 

Is it terrible and wrong to admit that I've been going with just the plain old: "That's how trees get ready for the cold winter honey, losing their leaves helps the big tree trunk stay warm." I mean its not scientifically correct, and it does not take full advantage of the depth of spiritual metaphor that fall really is in actuality, but I figure its the simplest step to one day talking about those things right? 

On a sidenote: I really enjoy the changing of seasons just because of their spiritual connotations. There is something comforting in knowing that all of nature experiences a falling away, dying, and darkness and that there is always a spring to a winter. I know, cue emo music here!