This friend will encourage the most idealistic parts of your nature, which sounds nice -- except that they could encourage you to step off the edge of the mundane world and into the stratosphere with them. While this will be fun and pleasurable and will make you feel a close kinship, it does present some problems. You'll be so idealistic when you're in contact with this person that you won't get much done in the way of tedious, day-to-day responsibilities.
You tend to be indulgent and enthusiastic, while your pal is rather gullible and impressionable, and that can be a risky combination. You'll talk each other up, and it could be hard to come down again and face reality when it intrudes, which it will have a nasty habit of doing. This confusing effect will have to be faced and dealt with; otherwise you'll just mislead each other without even meaning to.