In the context of this thread, gratitude stands for expressing what you appreciate about your relationship with another.
Do you see the problem here? If you like a flower, do you feel the need to thank it? No, right? A flower does what flowers do. So what's different about this scenario? The difference is you're using expression of gratitude as a tactic to manipulate.
If you're thinking, yeah, great idea, everyone manipulates, so what, you're a sociopath :)
As for the way you're using the word gratitude, to mean 'thanks' - sure, social norms dictate acknowledging other human beings in various ways - that's not what this thread is about.
The last time I heard this metaphor was in the context of avoiding too much flattery or dependence on praise of others. So, a well-adjusted person does things because they want to, or a have a responsibility to, without relying too much on praise.
I think this framing is useful for a person too reliant on others' opinions for happiness, but even within this framework, you can still feel happy when others appreciate you (while not reliant on the emotion). So, it's still a positive to give and receive gratitude, so long as both people have a stable sense of self and aren't reliant on gratitude for happiness.
If the flower could hear you, it would like to hear that it made you feel good. Flowers can't hear, but people can.
ugh, no, the difference is that your partner is a human being that can't read minds. if you expect them to know that you are grateful without expressing it then that may seriously hurt your relationship.
i'd rather think that if you believe that everyone expressing gratitude is manipulative then that makes you the sociopath.
