Hi Maximus,

I would say that knowing your true love means lots of things. You should be best friends, be able to communicate with one another and find each other physically attractive. Ideally you should know each other’s flaws, morals, habits, future aspirations. If you are aware of all of these things and none of them are dramatically different to yours then you should have a good chance at being compatible. Also if you are able to diffuse an argument or disagreement with one another then that is also a very useful tool in any relationship, which goes back to being able to communicate productively with one another.
I suppose you can never be 100% certain that the person you are with is your one and only. The likelihood is that you would be able to find someone else who you could potentially be just as stable with. That said, if you feel completely yourself around them and comfortable in their company, then that is a great basis for a relationship to turn into a great love.
If when you are apart you feel like a part of you is missing- then that is always a good indicator that you have begun to think of you both as a unit or team- and have a sense of togetherness with the other person.