The saying "you'll just know" is correct. If you feel completely at ease in your relationship, feel like you can trust him, and feel like you can share anything with him, Bob may be the one for you.
You kind of just know when you find the person you're meant to be with. There isn't any flashing neon signs that tell you, you just feel it in your heart. Maybe he isn't the one. You will know when you DO find the one.
