When I was in my 20's and even early 30's, I felt exactly the same way. However, by my mid 30's I started to realize that I didn't like being locked into any one social lifestyle. I liked having a few friends and the option of going out for a wild time, but I didn't want these people blowing up my phone and dragging me out every weekend. I had times when I would have much rather chilled at a family-style backyard BBQ, but I never liked the idea that such a social circle would encompass my entire social life. Sometimes I just wanted to chill out solo at home for the R&R. I wanted to keep all of it at arms length while still retaining the option of pursuing what I was in the mood for.
That is what you're probably going to want as well once you're north of 30, and it's easier said than done, but it CAN be done. All you really have to do is find those who feel the same way and understand your position, but you're going to need to keep in touch with as many as these people as possible, because while you may be in the mood for something particular one night, others may not be.