I was given some legal advice at one point which basically goes like this (paraphrasing):

You should of course read everything before you sign. But that’s not always possible or convenient and you may at times for various reasons end up signing something on-the-fly without reading it first. You should always make sure you get a copy of what you sign so that in the very least you can later review whatever you are on the hook for.

I adhere to the /keep a copy/ advice to a much greater extent than the /read before you sign/ advice. It’s about knowing your rights and responsibilities. So a bank once demanded that I sign something in order to keep using their service. It was long and in a language I did not know. They basically said I had to sign on the spot and I could not go home with it and bring it back later. I said, okay, but will you make a copy of this for me? Answer (paraphrasing): no, you do not get a copy. That is not our process. He also acted like I was weird for expecting a copy.

So I signed but pulled out phone and started to digitally image it. The banker snatched it away from me faster than I could get it in focus.

My mistake was not photographing first, then signing, then rephotographing with the sig if possible.

That actually happened pre-GDPR. The GDPR possibly accidentally solves this problem because your signature is personal data. OTOH, a clever bank could technically respond to an access request with just the signature portion of the doc and not the rest of the doc because the rest of the doc is not personal data – correct?

I don’t know if I will encounter this again but I would like to know if there any laws that prevent the bank’s non-transparent practice of blocking people from knowing what they agreed to. Banks often want on-the-spot signatures but I guess I should try to insist on bringing such docs home and returning later.

It’s quite inconvenient though because you can no longer just show up at a bank and get service. Banks have very narrow open hours on just 1-2 days out of the week. Lines to talk to someone are quite long, which makes appointments popular. So popular, that appointments are schedule a month out. So things are organised to exert pressure on people to quickly sign and bounce.