Why can't I login if I don't remember my security questions

The security questions help validate that the person signing in is the owner of the Apple ID.

For the security questions, if you are being told there isn't enough information to reset them, contact Apple ID Support.

If you don't know the answers, if the steps in the article below don’t work, contact Apple ID Support, although based on multiple posts I have read, they will not help you recover the answers to your security questions.

 Apple ID - If you forgot the answers to your Apple ID security questions.      *

From the article below. 

Without proof of your identity via security questions and other carefully selected criteria, Apple Support can't help you reset a password or perform any other actions on your account. These policies are audited and reviewed on a regular basis.

Security and your Apple ID.    *

Apple ID - Official Apple Support.    -

Contact Apple for help with Apple ID account security - Apple Support.  * (Link doesn't always load)  

Get Support   - Work through the screens to get a chat option. 

Apple Support schedule phone call. -

Apple on Twitter

Messages chat with Apple

You are welcome. If you can log in, you can switch to 2 Factor Authentication.

Apple ID -Two-factor authentication   *

Two Factor Authentification availability.   *

2 Factor Authentication - How to generate a recovery key.  *

Apple ID - Using app-specific passwords.   *

Apple ID - Two Step Verifications FAQ    *