They're called underthings for a reason!

Once AGAIN I find myself suddenly aware of the fact that my bra is completely visible through my shirt. This has happened multiple times in the past month or so. Too many to really be comfortable with. I think I've come up with some possible explanations:

-The lighting in my bedroom is kind of weak, so when I mirror-check after getting dressed, the headlights don't shine through
-I used to often wear a nude-coloured bra, but my most recent bra purchase was pure white, and apparently I need to learn how much that shows under many many fabrics (even though it's supposed to be not-so-visible, isn't it? And this explanation only partially works because it's not like I've never had white unmentionables before and I do not remember having this many problems.)
-Many of my shirts are very very very old and edging towards threadbare, so shirts that I'm sure I wore with white underthings a few years ago with no problems are becoming more problematic
-In the past when I wore opted constantly for the white brassiere, I was also less observant and just plain didn't notice the twin white beacons that were there.
-All of the above.

Did I just write a whole blog entry about my underwear? Ew.