I'm now thinking there's a possibility that my forum was created a lot earlier than 355,429. Proboards used to have server #s in the URLs. My URL used to be www.bigballofyarn.proboards13.com. Proboards had server #s that eventually went over 100. I'm starting to think that certain servers reserved certain IDs.
Proboards Support's ID is 1. My forum's ID is 355429. The ID of the most recent forum at the time of yesterday's post was 7034101. I went backwards from that # and found many recently created forums.
Forums 2-10 didn't exist. Forum 99 existed, but had no posts. So, I couldn't check its approximate creation date.
Forum 102 seemed to date back to 2005, but I created my forum in 2003.
Forum 109 seemed to date back to 2004.
They are numbered in order, but I'm now wondering if something else contributed to my ID.
My boyfriend created a test forum in 2003, 10 months after I created this forum, but his ID is 277640.
Perhaps I'll have to see if I can get more information.