The Beard Test is shallow, but it works:
If the object of your affection has a beard, ask yourself if you would feel the same way about them if they shaved it off. If they don't have a beard, ask yourself if you would still fancy them if they grew one. (Not talking designer stubble, either - proper beard.)
If the answer is no, it is just lust and you don't have to worry too much, especially if the idea of them with a beard has completely put you off ever attempting to seduce them. If the answer is yes, you are in
In terms of overall importance in life, creating the Beard Test far outranks anything I did at work today. You're welcome.
(Gentlemen: so far there is no lady equivalent of the beard test. I'm sure you're all snorting into your pint glasses at that statement but if you have any suggestions, do let me know. I am highly into gender equality.)