I think that all relationships start out as crushes. It seems to be natures way of making us fall in love . If you didn't check your text messages 30 times a day - that would be the odd behavior . The fantasy , the obsession is all part of a very natural process IF we have reason to believe the other person will develop feelings for us AND that it doesn't interfere with other aspects of our lives
A rational crush is fine , its actually fun !