I know you're pretty young, but think of it this way: are you exactly like you were when you were in first grade? Do you still have the same friends, enjoy the same hobbies, wear the same type of clothes, want the same thing out of life?
People keep growing and changing throughout their lives. Sometimes they grow together, sometimes they grow apart. And if they don't communicate, they can become strangers while living under the same roof.
That's what happened to me and my ex-wife.
Ten years on, I no longer knew the woman I married. And I didn't like the person she had become, either. I split with her a year ago. The last time I saw her was when we completed the sale of our house, last November, and I have not spoken a word to her since then. We even finalized our divorce by mail, through our lawyers.
We both run in different social circles, work in different parts of a big town, and hang out at different places. We literally don't have anything in common anymore.
Which is perfectly fine by me.