Haven't you ever felt during a conversation that you don't want it to end or wondered if you could stop the time for a while so you can keep talking/listening to the person you are having this interesting conversation with? And what is your definition for "Interesting" anyways?
What is the main reason for this phenomenon if I may call it because of its rarity?
Would it be the person, the subject or you?
In other words, Was the person that charismatic… that you were literally enchanted as he knew what language to use or he was empathetic enough to choose what to say, how to address it in a way you can relate to and therefore a kind of connection began to be established and maintained.
Some say, may be it's the body language or eye contact. but I personally think if sincerity wasn't there no connection can ever be made based on fake rules or ways.
Yes there are Charismatic people; they know how to communicate with people from different backgrounds, social standards and with different characters.
They can convince you of anything and have this ability to make you do things for them with great passion and motivation not as if you are captivated or hypnotized but with great convincement.
Another hypothesis; the subject …. Every one has favorite subject/s that whenever it's mentioned, it alerts all your senses and stimulates you mentally.
Another kind of subjects other than the favorite ones… the provocative ones, smart people sometimes need to be challenged and the provocative/controversial subjects triggers their need to prove how smart or knowledgeable they are, sometimes to the people and other times to themselves, it's like a mind battle.
The last one, YOU … what if you just wanted to have a nice and peaceful conversation with someone you can trust and freely talk to, what if you wanted to be heard, felt and appreciated, what if you were clueless and you wanted to get a mature opinion about something.
Sometimes we are so confused that we want someone to throw all our ideas, thoughts and feelings in front of, and start sorting and reorganizing them over again.
People are of great value and there is a reason for each one of us to be exposed to different situations and experiences. So that if you have the chance to share what you have learned with someone else, have a joint list of the rights and wrongs, it could make a difference to the two of you.
In the end, the answers are so many for the very same questions.