How does it feel to resign for the very first time?

I'll tell you... since I just tendered my resigation from an organisation that has sheltered me over the years and given me lots of opportunities to grow.
It was quite a difficult decision to make as I felt I was going to disappoint the management by betraying their trust and skipping off to greener pastures after all they've done for me. Knowing they've targeted me to be one of the leaders in the future makes it even worse. I think, "is it stupid to turn my back on this kind of trust to eat new grass that may be tainted with pesticide?" (metaphorically speaking...). I don't know the answer and I think I will only know after I take the big plunge and leave the comfort of my 2nd "home" of 6 years for the big bad world out there.
I know I'm taking risks by joining the new company. Retrenchment is not something they will not consider but hopefully, I get to reap some benefits from my experience with them before they place my head on the chopping board. I can't expect to gain much if I don't take risks right?
So, it is with sadness yet with strong determination that I take the step to new waters at this cross-roads in my life. I hope it leads to bigger things. If not, I will eat humble pie and come back to the fold... if they'll still have me.