Although you two won't be heading down exactly the same path in life, you'll understand each other's goals very well, and you'll be able to support each other in a really important way. This commonality could be based on similar past experiences, or it could just come from a feeling of familiarity and unity that will exist naturally between you. But whether you've had similar pasts or not, you will be able to offer each other solid advice based on your own experiences.
You'll play an important role in each other's lives. Even if you're quite different in your interests and your aims, there's a common thread that runs between you, and that will keep you united, running along parallel tracks. Talking openly about your goals, your dreams and also your anxieties will also help keep you both on track, because you'll be able to help each other get over any hidden fears -- of either failure or success -- and push through them.