we force an issue that we are not in favor of/don't support/don't like/don't want to get into, by constantly thinking about it. Holding it in our mind makes us unconsciously give it a lot of time...we analyze it, have conversations around it, add on all kinds of feelings to it, fan the flames it produces and....keep it alive.
If we just let issues we are not comfortable with filter through our mind, we'll be sparing ourselves a lot of grief.
As it often happens, the edifice (an ugly one) we have created around an unhappy issue usually falls when reality kicks in...and either it's not as bad as we thought it would be, or it just evaporates, or we find we can handle it...