There is no formula to use for this knowledge or understanding. No one can tell you what you are experiencing or feeling.
In my case it was a feeling of comfort, being best friends, a never ending desire to be with her, conversations that flowed easily, future goals that meshed, a sense of fulfillment, contentment, sexual attraction was good but not the mainstay, a spring in my step, the desire to hear what she was thinking and the sheer pleasure of seeing her smile when she saw me. I offer this not as a guideline, merely as a brief explanation of what I felt.
There is no such thing as a single love. You can and will have many--although you probably don't want to hear that now. The best you can do with the 75+ years you've been given is to love and be in love as much of it as possible. Fall in love, give people love, don't worry about whether this is "the one" or not. Life is not worth all that and this. It's just about enjoying each other's company before the journey of life pulls us through to whatever is waiting. So, the right person is "no one" and "everyone"...as long as you are open to love.
I don't know. I've been married for almost twenty years, and although I have always loved him, I didn't know he was my one and only for YEARS.
So, you feel so strongly you fight over the little things like which way the toilet paper goes, or whether the peanut butter jelly is on top--but can stop a knock down drag out fight about something BIG and come to a compromise, it might be love.
If your partner is your best friend, and you can talk about everything and nothing... it might be love. If you feel you share a brain and can finish each others thoughts--you might have been married too long, but it might be love.
If your partner is oblivious to flirting to the point that your friends and workmates are flabbergasted... he might be in love.
And finally, if a hobo asks you if you are married, and then when you say yes he asks you if you are happy, and you realize you truly are... maybe you've just been given a kick in the butt by the almighty--and it's definitely love!
When you will find a right person you will feel it . As I have found my best friend and I am attracted to her naturally .when I dont talk to her even one day I feel like some most important thing of my life has gone away .when I receive her SMS ,smile appears on my face. same things will happen to you .