Ask HN: Giving away all your best ideas to your employer

I'm about to start a new position soon that gives me a lot of creative control over a projects direction, having been in development for a long time with creative aspects like design and marketing mixed in this excites me - I've done similar work before and grew companies with this very work so I do have confidence in my abilities. I've always considered myself a creative person first and this new job may finally bring back the spark in life I've missed for a while.

I've already began the formulation of some ideas that I see can really shift this brand in a whole different league. With the preface of understanding what I'm saying may sound like a bit like I think too highly of my ideas (as ideas are infinite), I can't help but feel some regret that IF my ideas are correct and I happen to grow the company as hired to do so, that i'll be giving it away my best ideas away and not keeping them for myself.

I don't want to just go with the motions of my position, I would like to grow the company but is this always the best choice?

Has anyone had experience feeling like they've put too work, or has it actually paid off giving it your all in a position? I've had some bad experiences in the past so I'm hoping to hear some other points of view I may be missing