If I look in the fridge and there is no cheesecake, but I am not upset at what I see, that is because I wasn't expecting a cheesecake to be there, so its absence makes no impression, any more than the absence of a birthday cake in the shape of the Kingdom of Prussia at is greatest extent.
If Jonathan bought a cheesecake yesterday, and I look in the fridge and there is no cheesecake, just the packet and a few crumbs, I might be surprised, but, if I'm not doing sugar, I'm not upset.
If I was planning on eating the cheesecake, and that plan has now been frustrated, I am upset.
Resentment requires me to have an expectation and to be attached to that expectation (because I'm attached to the plan whose fulfilment requires the expectation to be met).