Verified answer

Rejoice! You will be able to get away with not shaving for a day or so and not look like a bum.

The answer is - genetics. Given adequate exposure to testosterone (and by 17, you have) the hair follicles that will produce facial hair have responded, and now you see the pattern that your genes programmed.

If you have a thick beard, by the time you're in your 40's you've had to shave about 10,000 times - a day off would be a blessing.

You don't fail @ life, you just fail @ beard.