Another parallel between TENET and another film, METRO MAALAI is that both protagonists are nameless. One of the reason is for us, the viewer, to put ourself into his shoe and experience his struggle.
In TENET it is about the being the protagonist (main character) of a person trapped in the forward and backward motion of time.
NOLAN using a nameless protagonist because he is pointing straight at us (by ‘killing’ him early in the film) and showing us these visions of the TENET (principle, belief and doctrine) of TIME that we are made to stick with. A world that we have been taught of (history, the past) and made us to prepare for (the future).
NOLAN shows us (apart from this EPIC writing and screenplay) the chaos if we constantly tries to change the past and the future
But HAPPINESS is when Robert Pattison managed to accomplished his final mission. LIVING IN THE PRESENT or VARTAMANA in Hinduism.
Maybe that is why PRIYA is from India and the Protagonist had to tell her that he is indeed the protagonist and in charge of his time - and NOLAN trying to tell us so should we all.
(In Metro Maalai, there is also a scene where everything else moved backwards in timelapse and the nameless protagonist walking slowly forward)
And truly, “By time, indeed mankind is in loss...” Surah Al-Asr