Have you ever laid your whole life down for your first love and just gave them your all and just gave yourself up wholly to him?

Did you ever come across your first love later in life? Have you ever met your first love again later on in life and dated? What is it like to see your first love after a long period of time? How long did it take you to find true love again after your first love? I haven't heard from my first lover in more than three years' time. Have you only been in one relationship your whole life?
I've only been with one person and that's basically been my goal since I was young enough to think about it. I wanted the man who was my first kiss to also be my future husband and the man I'm with when I'm old. Obviously I can't predict what will happen with my partner but I'm not the only person he's been with. I've been told everyone has to endure heartbreaks and multiple relationships if only just for the learning experience, making future relationships more successful. My partner has had some of that learning while I haven't. So I have some questions for women who have only been in one relationship or chime in with your experience anyway :)
Did you ever think you wanted to have other relationships and experience other people rather than with just one person?
Did you ever consider cheating or leaving your partner just out of wanting to know the unknown?
Did it end badly? Were you glad you tried another person? Did you regret ruining the original relationship?
Have you been with one person your whole life and can't be happier?