From years of observation and participation, this is my humble opinion. I hope to share some insights so that you could learn to love better ;)
Level 1: You don't know one another.
Level 2: You just know one another.
Level 3: You're beginning to know one another.
Level 4: You know one another and found differences.
Level 5: You know the differences and you know why.
Level 6: You know why and you accept the differences (because there's no two of the same you right?).
Level 7: You know the person is there only when you see them physically.
Level 8: You know the person is there if you hear from them (a text, a message, a phone call) even though they may not be physically present.
Level 9: You know the person is there even when you don't see nor hear from them. You just know.
Level 10: You know for a fact, the person is always always always always in your heart, even though they're not in your life anymore.
Could be your partner, your parents, your siblings, your friends, your whomever. I suppose especially in romantic relationships, 'knowing' is a form of assurance and security. Which is why, the fairer sex who seems forever 'insecure' needs to 'know' so much about her partner. Of course, it's easy to brush them away and call them clingy but truth be told, I'm sorry... there's nothing really you can do about it. Because insecurity is a personal challenge. Sure you can help by making it 'easier' for them and in time, they may be inspired to let go which I'm sure all your efforts will be much appreciated. And it will be paid off by a beautiful wonderful understanding partnership of two diverse personalities. But first, you've got to hack it yea?
Sounds like a lot of work? Well, nothing worth having is easy anyway, no? Good luck and happy loving one another ;)