All this notwithstanding, if you plan to travel back in time, you should take precautions.
(cautionary note) Just because a comet is hurdling toward earth, don't drink poison punch so your "spirit" can join with the Mother Ship following in the comet's tail. There likely is no mother ship and all you'll end up doing is providing work for grave diggers.
If you hope that traveling to the future will somehow improve your lot in life, you may be wrong. It might suck a whole lot more than it does here and now.