FYI: If you watch financial advertising, you know that you should spend your days tracking your portfolio, trading frequently, and, well, tracking your portfolio.
Oddly enough, many people find other things that they would rather do in life, such as reading a book, traveling the world, or sorting bolts in the garage. If you're one of those people, then you probably should invest in a target-date retirement fund.
Regards,
Ted
http://www.usatoday.com/story/money/2015/03/13/investing-target-date-funds/70228638/