I was fairly young when my Dad taught me to use a hammer. He taught me well and made sure I had plenty of practice (siding - drywall - roofs).
There are certain ways to do things... like pulling nails.
This is an approved method.
This one works too. The hammer is always under control.
This is NOT an approved method.
It is NOT a good way to straighten a nail that went in crooked.
It does NOT keep the hammer under control if the nail head happens to break.
Because when that nail head breaks... the hammer could hit YOU on the head.
There will be instant intense pain. A goose egg will form.
And then you will have a lovely black eye for several weeks to remind you to listen to your Ol' Dad!