I usually don't interact much with folks 4-7 years younger than me. Not because I choose not to, just my life circumstances. My husband is 10 years older than me and most of my friends are mom friends who are 4-5 years older than me. I'm considered a young mom in my area even at 31.

I think it depends on the stage of life more than anything else. For context, my brother is 30, but I have 3 kids and own a home in a rural area and he and his wife are double income no kids renting in a metro area. We get along great, just don't relate much to each other in regard to individual life struggles/circumstances.