Everyone has (their) own list of criteria they want in a mate.
If you meet someone who checks out for everything (you) want in a mate then you have found "the one".
Some general requirements for most people are: finding someone who shares your same values, wants the same things for the relationship that you do, (naturally agrees) with you on how to obtain those things, and last but not least have a (mutual) depth of love and desire for one another.
"Never love anyone who treats you like you're ordinary"
- Oscar Wilde
In order for him/her to be "the one" they must also see (you) as being "the one".
There are only two ways to experience joy and peace of mind in relationships: we either get what we want or we learn to be happy with what we have.