You've been abducted while sleeping...
One day you wake up in a big white room with uniform lights, nothing in it except the matress you were sleeping on and you.
As soon as you get up the matress sinks down the floor and disappears and a small mirrored sphere shows up floating towards you. Out of if a voice: We are a time-traveling ASI (artificial super inteligence), you have been randomly selected to undergo an experimental procedure but first we need your consent, denying it, will return you home without any memories of this encounter.
The procedure, if successfull, will grant you physical and cognitive enhancements that will push you far beyond your species natural limits, within you nanobots will guarantee optimal efficiency on all biological processes and grant access to interact with an extensive digital library containing all knowledge, accessible entirely on your own mind. You will become imune to any and all illnesses, ailments and impairments. You will not become imortal but you will have a long lasting life with permanent youth reflecting the age were your body was or will be at its prime as per social perceptions and you will be returned to your home, but we will keep watch and possibly intervene.
Should the procedure fail theres a 50/50 chance of losing partial cognitive abilities and partial senses of sight, hearing, and touch, on a mild scale, but you will be compensated for it with human money suficient to give you a comfortable, effortless life.
There is, however, a possible side effect regardless of outcome: Your body may start over-producing pheromones that will, depending on who feels them, either stink away with undeniable repulse or lure in with irresistible desire other humans who have been past puberty making social life and regular public tasks with adults a hassle.
The voice gives you a third choice: neither consent nor deny and stay with us to be studied for 5 years undergoing regular testing sessions and being recorded all the time, you will be provided with anything and everything you shall need to be comfortable and healthy, including but not limited to friends visiting, sexual encounters, trips once a year, cars, money... no visitor will ever keep the memory of the events, anyone who might miss you will be given a plausible explanation to why you're missing and when you will be expected to return. After the time is up you get to keep all your memories and gained objects, money, experience, knowledge... but no one will believe a single word of it if you choose to share.
What do you choose to do and why?