There's a reason certain smells change after 40 that has nothing to do with how often you shower — and Japan named it decades before anyone in the West gave it a second thought. This video walks through ten specific, research-based habits behind that shift, from the four spots on your body you can't actually reach, to the one word in Japanese that English still doesn't have.

TIMESTAMPS
00:00 – Introduction
01:12 – The Japanese term behind this: kareishu
01:57 –  #1 The four spots you can't reach
03:09 – #2: The soap aisle America doesn't have
04:25 – #3: The fabric holding onto it longer than your skin
05:19 – #4: A second, different compound (diacetyl)
07:03 – #5: How the scalp actually needs to be washed
08:16 – #6: Why cologne can work against you
09:23 – #7: What diet has to do with it
10:46 – #8: Walking vs intense exercise
12:02 – #9 Airing out the home
13:23 – #10: The word English never made (sumehara)
14:13 – A few personal thoughts
16:05 – One question for the comments

If one of these ten surprised you, it's worth sharing which number it was in the comments below.