You don't have to be "deep" or constantly talking about profound issues. You just need to be "in the mix" so that you venture outside of your box. People who don’t peek out and over the lids of their cardboard hovels live in very small worlds. They may follow others into change, but they do not own it.
One way to clarify who is in the mix and who is not, is to ask, "Would I go to this person for advice when some significant life issue confronted me?" Not just for encouragement or some sage piece of advice--but because this person is a fellow struggler.
These types of friends and acquaintances are "in the fight" to move beyond white picket fences and 9-to-5 jobs. They whet your appetite for substantive relationships and make you want to become more than what you are. These are friends who are open to paradigm shifts in their own lives. They are not just focused on “straightening you out” so that you will become more like them. They want to grow like you do.