Babies have no worries except for food, sleep, and basic comfort. Yet- babies can be unhappy too. Dogs can often be unhappy as well. Now- not being entitled and not being greedy are good values. However anything taken to extremes gets a bit silly. If travel makes you happy, if cars make you happy, whatever it is- we don’t control what makes us happy. What’s more, if we were happy with low quality food in a bowl, pooping on the ground, and maybe a stick or a squirrel to chase- none of this would be here. There’s a thin line where if we don’t try for more or ask for more, we will get exactly that. No medical breakthroughs, no mass communications or electronics- while in some ways that is better, in others it’s worse. Say you were born with a heart condition? Suddenly instead of a long full life thanks to modern medicine- you for slowly and painfully. It’s all about balance. Don’t be afraid to try for more, but don’t let the quest for more make you unhappy with what you have.
And as far as I know, starvation isn't a very happy activity