I fell hard and fast for my husband. I could trust him with everything and he made me so incredibly happy. I want things out of life. I want to experience things and see things but nothing the world could offer me compares to what my husband gives me. Totally in love. There were no doubts when we decided to marry. In fact it felt like the natural progression of our relationship. There are still no doubts. I'm fiercely loyal to him. Still "twitterpated". I tell girls all the time not to settle. Wait for "the one" to come, because you'll know it. There's no mistaking it. Once you find that person, nothing else exists.
It would most likely be when you tell each other that you want to be together for the rest of your lives. Its really just a personal, and special feeling, that's more than love itself. You will know when.
You'll know when that person is the one because you will not want to live without that person! It'll be like you can't breathe unless that individual is a major part of your life! You'll feel it in the depths of your soul