Are you at similar stages of your life? And are you on the same page or have compatible views about:

• Financials
• Kids
• Religion
• Sex
• Relationship boundaries
• Distribution of household chores

Disagreement about financials is a top reason for divorce.

Possibly important depending on circumstances:

• Pets
• Getting along with each other's family and friends
• How to balance common and separate hobbies/activities/etc.
• Politics
• Privacy
• Diet