Well, I think it's a better choice to make friends with people of different ages other than of the same age with you.
This is because, people in different ages can provide me with more effective problem-solving solutions from their own experiences, especially for the situations those I never met before.
For instance, I have a friend. He is 10 years older than me. Once I had an interpersonal dilemma and really didn't know how to deal with it. I went to him for help. Finally, he came up with an excellent suggestion for me to have the problem solved easily.?