Forgetting someone's name will only become an embarrassing situation if you turn it into one, so if you ever run into someone and can't for the life of you remember their name just keep cool and ask them again.
Don't have the moxy to admit that you can't recall their name?
Just don't start calling people by some cockamamie nickname or you'll never learn anyone's real name, and you probably shouldn't just call them by some random name either unless you're prepared to feel really awkward.
And if you were okay with awkwardness then why didn't you just ask their name instead of doing the whole song and dance?
These tips and more can be found in this comic strip by Charles Higson, it'll make you question whether you'll want to meet another new person ever again!