Well, just in your example/world, maybe, you're the pro. But you cannot make Norton Community more PRO.

I fix computers...

I maintain hundreds of computers...

Fine, how to become a member of all the forums around this planet? And, how many online forums are in existence?

If you are talking about forums dedicated to a specific topic (cars, sports, technology, hobbies, etc.) and powered by one of the most popular forum software platforms including vBulletin, phpBB, SMF, and others, then the answer is slightly north of 110,000. 

Here is a count of forum platforms and the number of communities on each platform circa Q2 2015.

Forumotion – 14,459
XenForo – 8,781
SMF – 25,811
phpBB – 27,073
vBulletin – 44,540
XMB – 127
Vanilla 2,154
Discourse – 697
Liquid – 31
-Lefora - ?
-Yuku - ?
ProBoards - 3.8 million
InvisionFree: 2.7 million
ZetaBoards: 120,000
Reddit - 500,000 subreddits
Lithium - ?
Jive - ?
IBM - ?
Google Groups - 32,000
Yahoo! Groups - 60,000 sites
Discuz - 160,000 
Sina - 50,000
Sohu - 50,000
Baidu - 500,000 
Salesforce - ?
Facebook groups- ?