It would appear that you are correct. There is a bug in the 2FA addon we're using that will ask you again every 24 hours (if you log out of the forum) regardless of whether you check the 'don't ask' box or not. 2FA is built into the core software in the next version although they don't yet have Yubikey support so I'm not sure we'll activate it.
Here's a really terrifying statistic; an unpatched PC on an open Internet connection is expected to last 40 to 200 minutes (yes, the upper bound is under 4 hours) before it's hacked: What’s Your Internet Survival Time? | The Gotham Blog - and that lower bound may be optimistic (earlier research suggested around 15 minutes)