If you have been to London for a week, they will have spent a month there. If you have been to Kenya, they will have transversed the whole of the African contintent, on a skateboard, carrying their 60 kilo pack on their head.
This kind of traveller needs to outdo any fellow traveller with their stories and catalogues of destinations and adventures.
The intereseting ones can recount mesmerising, self-depreciating and often amusing tales. More often though, the "go one better traveller" can be downright boastful bores!