1. You look all the way down food ingredient lists, looking for things you know the structure of.
2. When you look at the ingredients list, you curse them for not using the proper name.
3. You refer to cooking operations by their lab versions (filtering off the pasta, refluxing the stew).
4. You get a certain satisfaction when you casually tip some compound onto the scale and it comes out as exactly the amount you wanted. Well, within experimental error.
5. You use the term “within experimental error” with regularity.
6. You can identify certain chemicals by smell, at a very low level.
7. Conversely, there are whole classes of chemicals you cannot smell at all that provoke an animated response from your (non-lab) family and friends.
8. You have a separate set of clothing for work not because it is nicer/more professional but because you don’t want your home clothes to have a series of small holes in them.
9. There are about 2 degrees of separation between you and every other chemist in your immediate geographical location.
10. When you say you are bringing some work home with you, your family are immediately concerned for their safety.
Excellent list from the Chemical Space blog