I'm confused about whether I really need to apply sunscreen every day.

I often heard that I should apply sunscreen even on days when I stay indoors.
I started wondering if it might be okay as long as I don't sit by the window for too long.
I'm worried because sometimes my skin feels stuffy when I apply sunscreen.
I know that UV protection is important, but I'm not sure how much attention I should pay.
I'm also confused about whether the standards change depending on the season or the weather.
It's also unclear if I really need to reapply it, even when I'm out for a short time.
Considering skin aging, it seems like applying it every day is the right thing to do.
I want to know what the realistic sunscreen standards are.