To love someone is to see the best in them. To know their flaws and their failures, but to look past that to see the great things about them. It is a fusion that melts them into your soul and makes them a part of you. It creates this surreal bond between two people that could even be described as a supernatural connection of spirit.
Love is when it isn’t about sex anymore. When their body isn’t the first thing you notice when you see them. It is when you see their face and it makes you smile, or when you fight with them and feel poorly for the argument.
Love becomes addiction. It turns from someone that you hardly know into someone that you couldn’t live without.
In the proper time and maturity of any loving relationship, inevitably, the two will become addicted to one another, so there is no difference.
However, if one finds themselves obsessed with someone, i.e. having feelings of jealously for ridiculous reasons, finding it necessary to drive past their house to see if that person is cheating on them, large and unreasonable trust issues that garner irrational feelings of anger and jealousy, then that person is not in love.
That person has decided that the other person is their property. If that person cannot be away from your sight, or live their own life without your constant interruptions, or investigations to see what they are up to, then there is no love there. It is only a controlling and obsessive scenario that has historically been the precursor to worse activities.