Buy and Hold Forever: My Approach
I'm not a buy and hold forever guy. A good investment today might be a terrible investment 20 years from now. But I do make one exception: When I buy a stock and it doubles, I sell half (get my original investment back) and hold the remainder (which was essentially free) "forever". This pays off a lot more often than it hurts me. (And my biggest investing mistakes have probably been the times when I failed to follow this advice- before I formally committed myself to this approach).
Caveat: "Forever" doesn't really mean forever with me. If one of my "buy and hold" stocks lags for 7 years or more I might consider selling it, though I'll be reluctant to do so unless I have good reasons for thinking that it is in permanent decline.
Wouldn't it be great if every purchase eventually ended up on my "buy and hold forever" list this way!