This is why I usually reply to messages straight away. As soon as I see whom it's from I hit reply. Reading along, the ideas rush to me and I write them down as they are fresh in my mind. Before you know it you're done, and it only took 3 hours... but it didn’t feel like it, because you were having fun! You were interested by what they were saying, and your response was enthusiastic and inspired by the moment -- not 3 weeks stale!

I usually subconsciously format the message as I go along, making it look all purdy, but more importantly clear and neat! I purge old threads and old comments, leaving just enough so they know what I'm talking about in my reply. Even then they inevitably get awfully large. If this happens I usually try to, clear out all the threads which look like this:

> > > > > > > > > > > > > > > hahahhahhahah
> > > > > > > > > > > > > > hahahahahahaha
> > > > > > > > > > > > > hahahahahahaha
> > > > > > > > > > > > hahahahahaha
> > > > > > > > > > > hhahaahahhahh
> > > > > > > > > > hahahahahaha
> > > > > > > > > hahahahahaha
> > > > > > > > hahahahahaha
> > > > > > > hahahhahaaah
> > > > > > haahahahaha
> > > > > hahahhahaha
> > > > hahaahahaha
> > > hahahahahha
> > hahahahahaha
> hahahaahaahh
hahahahahah

(This is actually out of a real intellectual message! Grin...)

But even if the distinction isn't that easy for you, you can always ask yourself, "does this matter?", "do they care?", "is this really worth replying to?

In this way, you can cut down the correspondence to what really matters, and save yourself from inevitable self-destruction! Its worked for me so far...