This is a really hard concept for humans in general... but times change. Tools that were invaluable in 1999... are in fact outdated. I wouldn't dream of telling you how to log in to all those different email addresses... anymore than I would bother explaining to an ice delivery man in 1915 the importance of a compressor in a refrigerator.
In 1997 there were still companies clinging to their individual workstations...refusing to network... carrying around individual files from station to station with floppy disks. Just like in 2012 there will still be companies with employees checking 4 or 5 different email accounts.
You don't need any of those accounts. There are better ways of communicating.
Also...
Its not 2001.
You can get inflight wifi.