Almost all girls and women spend a lot of time before the mirror. But I dare say that it's not good, moreover it's a bit dangerous! Why?! Hmm… Will try to answer this question in a clear and convincing mode.
When you look in the mirror your eyes fix changes, happening about your appearance with every passing day. The signal about it gets to your brain and the latter starts to actively inform you about wrinkles, going to appear on your face. (I hope the statement that our brain has a great capability to program our body, stands beyond any shadow for you.) Thus, since your brain's informed about coming wrinkles, they will start deepening on your face or neck.

So, to be young and fresh, forget about the mirror and speak to yourself every day that you look nice and your face is still very young and smooth!