I read your note and just want to remind you that you are in this lifetime to live your life.  I think it is admirable of you to want to continue your allegiance to your current employer.  However, you need to grow and experience your career, whatever it may be.  Remember back in elementary school?  Aren' t you glad you moved on to middle and high school and then graduated to bigger things?  That' s a pretty rudimentary example, but that is what life is about, experimenting and trying on situations to see if they fit.  It keeps you growing and makes you interesting to other people.

I think, since this person is your boss, he/she will understand that you want to move on after 2 years.  If he/she has difficulty with your decision, that opens the door to discussion for negotiation of what you want to keep you there.  Just think about it, some people have been in positions their entire life and have the same thing to talk about over and over...Time to get out there and find out what is waiting for you.

My suggestion is that if you are going to leave and want to not "burn bridges", do the polite procedure of giving a timely notice in writing.  Maybe your boss needs to know how much you appreciated him/her and working for him/her. You know, the social thing.