A youngster may never have been in love, and may not even know what it feels like. They may confuse love with all sorts of other feelings. Have they fallen in love or is it something more prosaic? Is it just a crush, an obsession, fondness, friendship, or simply lust? Asking other people may not help because it's such a personal experience and impossible to explain.
There are plenty of examples of youngsters who thought they were in love, rushed into marriage, and then a short time later realised it wasn't love at all and had to divorce.
An oldie like me however knows exactly what love is because I've been in love with Jenny for 43 years and the feeling is well established. I have no problem telling love from other similar feelings. When I fell for Jenny it was the first time I had been in love so it only gradually dawned on me that that's what it was (I didn't really love my parents, I appreciated everything they did for me but that was it).
Is it love if the feeling isn't reciprocated? That's something I'm not sure of even at my advanced age. I thought I was in love with a bookshop workmate but she never reciprocated so was that love or just a one-sided crush? And what about all those people who say they "love" a public figure - a show-biz celebrity or one of the Royals - even if they've never even met the person? How can that be any more than devotion or admiration?
What is love? It's complicated....