Dude, I don't know how you did this whole thing in 5 hours. It has taken me considerably longer by a factor of X to get even to where I am on my New Zealand one. The writing part isn't even the hard part; it's the reviewing, editing, uploading, and posting of the photos which are killer.
The writing itself took 5 hours. I probably spent 3 hours choosing and captioning pictures, which took a lot longer. I uploaded the pictures overnight, so all I had to do was select which of the 1700+ images I wanted to share. Plus, I had DW edit it, as she can find errors really quickly. If don't include the uploading time and the editing time, it was all done in about 8 hours. With those two added in (and editing the monkey video), it took closer to 10 hours.
Another reason I do it on the plane is because that way I'm not distracted. No wifi on KL or AC (my longhaul last summer) so nothing to do besides watch things on the IFE or do a TR. Once I get home and have internet all bets are off.
I think the reason I'm able to get it done in that amount of time is because I write very concisely. I think you write a better story, which is a lot more fun to read (IMO), so that takes a lot longer to write. Plus, I don't try to come up with cliffhangers.
+1 And the further along the road it goes, the more time I have to spend remembering what happened. Yehoshua is just a machine.
That's another reason I do it right away (and take a million pictures and save receipts): to refresh my recollection in case I forget things.