Well, just like with any computer program, they always disclaim not to loos your password and make it easy to remember. That is the whole point of password security, so you're the only one able to use that secureddocument without restrictions (or elevated privileges).
If you forgot your password then obviously you can't open that document using this method. You will have to print to PDF which is basically flattening the original document and all you PDF objects, calculated fields, checkboxes, dropdown menus, etc. will be gone for good.
Have you considered contacting Adobe Customer Care directly and see what they can help you with on their end?
My assumption is that when you refer to “they” you are referring to Adobe and assuming that is the case, I know of no one in my company who advises that anyone should create a password that is “easy to remember.” As you indicate, that totally defeats the purpose of password protection.
There is absolutely nothing that Adobe Customer Care can to to open a PDF file that is password protected. Adobe doesn't secretly keep copies of passwords applied to PDF files, nor is there any “back door” provided either by the PDF specification or built by Adobe to bypass password protection for opening a document. That password protection front-ends document encryption.
Thank you for clarifying Dov.
My reply didn't came out right. I assumed Adobe could've helpe with this. I should've stated it was my personal opinion not Adobe's statement or posture. I also was referring to "they" for the computer program disclaimers not Adobe. And when I said easy for the user to remember I was referring to something like the user can easily remember to cipher. I was not implying easy passwords to crack.
For example, #1K4nr3MemBRdIz-ECly&
The password above complies with strong password requirements with at least 2 numbers that are not repeated twice, at least 2 special characters(or symbols) that are not repeated twice, at least two upper case letters that are not repeated twice, at least 2 lower case letter that are not repeated twice.
If I put it together in a phrase that I can easily remeber in English, the above example denotes or suggests:
I just added special character that also only myself can (or should) remeber easily.
1 = to subsistute the pronoun "I" (referring to myself... in first person singular)
K4n = to represent the word "can" (very easy to remeber 4 as an letter "A" for example )
r3MemBR = "remember" (using the same analogy in my line above for the word "can")
dIz = "this" (demonstrative pronoun to point out a singular item or object)
ECly = "easily"
Nonetheless, there is nothing that any of us can do to assist ... We aren't Claire (as in clairvoyant)! 😁
LOL!! all acknowledged.