There is an all too human desire to listen to other peoples confident predictions.
Professed believers in "the efficient market," and "passive investment" often feel insecure about sticking to their plan to stay diversified when the common wisdom is that "interest rates can only go up from here."
I am not immune to this impulse, and will admit that I have felt uncomfortable buying long treasuries for the past few years. (But I did anyway.)
One of the nicest things about a prespecified investment plan, such as "buy and hold" is that you can supress your own human impulses and fill in the numbers, ignoring what you want to do. In other words, you can get on with your life, and stop getting in your own way.
This is a great article from Larry Swedroe, about how unwise (and costly) common wisdom often is...
http://www.etf.com/sections/index-investor-corner/23719-swedroe-the-surprising-lessons-of-qe.htmlEnjoy!