Identification in Wisconsin

Here are some things I've done in the last week:

1. Bought beer.
2. Bought a cigar.
3. Got cold medicine.
4. Re-established a dormant account with an online retailer.
5. Rented a piece of equipment.
6. Purchased some household chemicals
7. Voted.

Guess which one of these items was so unimportant that I didn't have to validate who I am with an ID of some sort? Don't strain yourself, now.