A-ha! But that would create a time-paradox, for the Jeffrey who hasn’t gone to the future (J1) would have probably asked the Jeffrey who has gone to the future (J2), who might tell him what happened, which might cause J1 to not go at all now that he knows what happens, but that would make it so J2 never existed to tell J1 about what happens, thus making J1 have to travel to the future, and possibly causing it to start all over again.
A-ha! But that would create a time-paradox, for the Jeffrey who hasn’t gone to the future (J1) would have probably asked the Jeffrey who has gone to the future (J2), who might tell him what happened, which might cause J1 to not go at all now that he knows what happens, but that would make it so J2 never existed to tell J1 about what happens, thus making J1 have to travel to the future, and possibly causing it to start all over again.