Ted is the narrator of the entire story and its very suspicious how every single one of the woman he dates in the show are very attractive and it seems he's hyping up how attractive all the woman he dated were especially seeing as he's a pretty average looking guy.
Another point to promote this theory is how much of a dick all of Robins ex's are. In the episode "Slapsgiving" Ted mentions how when your ex is dating someone new your brain tends to accentuate their flaws and shows how he sees Bob as a very old man even though he's only about 40 which is just not great for narration anyway seeing as he'd biased against all of Robins ex's as he's in love with Robin through the whole show and he may be accentuating how bad Barney was through the show as he is Robin's ex and may be exaggerating how much of a slut/womaniser he is.
I know these are old theories that have already been posted here but I just was thinking about this and wanted to share my thoughts.
What do you think?