An English saying suggests that 'absence makes the heart grow fonder' while another states that 'out of sight is out of mind'. One does not need a soothsayer before realizing that these quotes are contradictory, on opposing ends of contrasting universes.
While the first suggests that people value and become more attracted to those whom are physically unavailable to them, the latter explicitly concludes that once there is no physical connection, mental and emotional attraction level drops to zero.
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I wouldn't want to outrightly conclude that both quotes are wrong. Let's just say people get to make their own choices. After all, that's what makes us human beings. The choice of attraction or value placement is not dependent on physical presence or absence but on what each person decides to do.
The strength and genuineness of someone's love or fondness for you is tested and revealed through many means, one of which is physical distance. This is suggestive of platonic and romantic love. And while some people and attracted more to those they see regularly, others tend to place more value on strangers or those who are deliberately 'scarce' to them. For this second set of people, the saying 'familiarity breeds contempt' gives an apt description'.
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Nonetheless, this does not mean that a love that diminishes once you're 'out of sight' is fake. It only suggests that such love could not stand the test of distance and should probably be strengthened and invigorated before being made to go through the pains of deliberate absence. My submission however is that: "Either in a love relationship, among friends, family or a public community, the quality of effort and attention given to love goes a long way to determine how long it will last whether physical presence is active or nonexistent".