Do I have to apply sunscreen even on days when I stay indoors?

Don't you ever really struggle with whether or not to apply sunscreen when you stay home all day on weekends or holidays? Haha, it's a dilemma I face every time. I consider it a given that it's essential when going out, so I make sure to pack it meticulously, but I feel like my skin would feel stuffy if I applied it indoors. On the other hand, if I don't apply it, I worry that the sunlight coming through the window will damage my skin. Am I being too sensitive...? Actually, I think I'm more concerned because I've heard that UV-A rays penetrating glass are the main culprits behind skin aging and age spots. But applying it is actually quite a hassle, isn't it?

Some people say you absolutely have to apply it because UV rays are emitted even under indoor lighting, while others say it's actually bad because your skin can't breathe if you apply it even indoors, so I really don't know which tune to follow lol.

It’s not like I can live with blackout curtains drawn all day long.