Living in close proximity to people whose interests or life styles vary vastly from your own is uncomfortable. Factor in differences in age is often also problematic as is whether tenants are single, married or have a child.
Such variables change the level of empathy or apathy that seriously restricts respect for immediate surroundings not just other humans in the periphery. As a human ages, so does their empathy expand raising the level of respect for others (typically not always). Younger people have not developed a sense of the world beyond themselves and their own generation. As they begin to have serious relationships and become family oriented (whether this is oriented around just very fast friends or having children of their own) their world expands greatly. Of course this view continues to expand as they age into stages of middle and golden ages too (again, typically, not always).
Human beings find, often, that they reduce the number of actual ‘friends’ too as they age and those they trust and find comfort with can be counted on one hand because such relationships are no longer frivolous as when a teen and young adult. That also means that a sense of privacy becomes ever more important and close living quarters more ‘invasive’.
Sometimes the less said the better at least spoken directly. When there are viable reasons for discomfort, it is wise to let a landlord or office know and if there is fear especially. I’ve been in positions where I knew well that surrounding tenants were dangerous and eventually I had to move.