First, with the passage of time, the friendship of student days will gradually fade away.
Second, everyone went to different universities and majors, and their hobbies changed.
Third, we work in different cities, with less contact and different circles.
Fourth, after work, everyone has a clear goal and doesn't care much about things outside of work.
If you cherish the friendship between you, take the initiative to attend his wedding. We can get together more in the future.
You don't have to go if you don't mind him not telling you. Life is long, and you will have many friends.