Ditto lots of what others have said.
I've been stupid in the past and given out information to people who called me claiming to be from the bank or a charity or whatever. No more.
These days, if someone calls claiming to be from a charity and asks to put a donation on my credit card, I say no, send me something in the mail. Then I can verify that any address given really is the address of the charity. Etc.
If someone calls claiming to be from the bank or a credit card company or whatever, I make sure they are giving me some information that a scammer is unlikely to know. If they don't, I say that I will call them back, then I look up the phone number on the bank's web site. Companies won't normally tell you your account number for verification, but at a minimum they should tell you the name of the company, and not just "the bank" or "VISA". If there's a problem with a particular transaction, they should know all about that transaction, like when it was made and the amount.
In my experience, most scammers don't go to a lot of work to research your life. They call and say "this is the bank" because they don't know what bank you patronize, etc.
Most scammers are pretty lame. I get lots of scam emails that I know are scams because they are filled with spelling and grammar errors. I could believe that Microsoft would send an email with a grammar error. But Microsoft is not going to send me an email with 20 grammar errors. That's a scam. Etc.
I'm sure some scammers take the time to do some research on you. There are plenty of ways today they could find out your birthday. They could steal your mail to find out the name of your bank and your account number. Etc. To the best of my knowledge, I've never run into a scammer who did that much work. Probably I'm not rich enough to be worth special effort. It's easier for the scammer to just dial through a bunch of numbers or send out a bulk email and try dupe the most gullible people. Or people who are usually smart but just have a moment of carelessness.
But my point is, if they can tell you one or two things about yourself, they are PROBABLY legitimate. I wouldn't beat verification to death. But get SOME verification.