After a fight with a friend, I calmly analyzed the necessity of indoor UV protection.

I just got back from a trivial argument with a friend, and I'm feeling a bit uneasy. I was sitting in the living room, basking in the sunlight, when I mentioned that I should wear sunscreen indoors. My friend chided me for being too picky. I was so taken by that comment that I brought up data showing that UVA rays can easily pass through glass and penetrate deep into the dermis, accelerating aging. The mood suddenly soured. Come to think of it, my argument was perfectly logical, but it ruined the mood. My personality just can't let things go. Why do we dedicate ourselves to our daily home care routines? Ultimately, it's to preserve the skin barrier and maintain elasticity. Applying expensive regenerative creams while neglecting the most powerful destructive factor, light, is like pouring water into a bottomless pit. Considering the potential for cosmetic ingredients to deteriorate due to exposure to light, sunscreen, a protective mechanism, should be seen not as the end of home care, but as the beginning. My mood has calmed down, but after applying sunscreen again, following my logic, I finally feel a little more at ease. I'll probably send my friend a gentle message of reconciliation instead of logical persuasion later, but I just can't give up this stubborn routine. Everyone, even indoors, by a bright window, never let your guard down.