I cannot understanhd for the life of me why it is so necessary that I must wear sunscreen nearly everyday in order to "keep from re-darkening". I am a student who leaves my home at 7 am when the sun is not very well in sight and I spend my days in a school building where sunlight is not directly permettied much entrance through windows. I then make my way home after 8 hours of this via underground subways and I then walk under shade and with an umbrella if I happen tobe in direct sunlight. I spend only.. forty-five minutes outside(cumulatively) for the whole entire day... why again is sunscreen so completely "NECESSARY??".

I have a question for you in order that I can understand your issue: Who is recommending that you wear suncreen so often and what are their credentials ?

Everyone's skin is different. You should do what you think works for you.