> And you got points even if you were completely wrong.

One of the oft repeated ideas is that you got points for closing questions.

You don't. The only ways to get rep on stack overflow is described at https://stackoverflow.com/help/whats-reputation

    You gain reputation when:
    
    question is voted up: +10
    answer is voted up: +10
    article is voted up: +10
    answer is marked “accepted”: +15 (+2 to acceptor)
    suggested edit is accepted: +2 (up to +1000 total per user)
    bounty awarded to your answer: + full bounty amount
    one of your answers is awarded a bounty automatically: + half of the bounty amount (see more details about how bounties work)
    site association bonus: +100 on each site (awarded a maximum of one time per site)

You do not get any points for closing a question.