It's true that drugs like MDMA or Mephedrone can cause an outpuring of feelings very much similar to what you feel when really loving someone (in my time in university, Mephedrone used to be called "The Big Love" by partaking students, it was legal then). However, a sober examination of those feelings after some time may reveal to you an underlying "fakeness", in the sense that what you were showing was not really a…
Perhaps it's because I was very involved in theatre at a young age, but I feel I can manufacture that kind of affection endogenously quite reliably, what stops me from doing so more is a host of complex counterfactors. It's these counterfactors that I feel substances like these suppressed.