You're moving along a certain path through this life, one that will lead you into your future, including plenty of karmic development milestones along the way. When you become involved with this person, they will help you to focus on your path and move in the direction that's best for your personal development. They'll set an example for you of responsible behavior, and they will also give you practical advice for your own life -- what steps you should make in your education or career, how to deal with family concerns and more.
You'll find that they have solid ideas that you can relate to, and when you follow their advice, you'll take big leaps forward. Even more than that, this person may take a firm hand with you. They will set their standards high, expecting a lot of you, and you'll feel obligated to perform up to their expectations. They may even have a limiting influence on your life if you two become a long-term item -- they might disapprove of some habits or behaviors you've never thought twice about before, for example, and will gradually convince (or coerce) you to change your habit to a better, healthier one. This could be an uncomfortable process for you in the short run, but in the long run, it will help you develop at a personal and karmic level in a way that you might not progress on your own.