I have been wrong when I claimed that negotiations take place all the time.  There are times when it doesn't and times when it shouldn't.  I won't comment here and now as to when negotiating doesn't take place, but I will identify a two times when we shouldn't be negotiating.

1.  Don't negotiate when you're under extreme pressure or experiencing a high level of stress.  While those are seemingly obvious times when our bargaining capabilities are impaired, people still extend themselves and press on.  Picking you time, as in picking your battles, is a sound selective strategy.  Watch out, there are occasions when others will impose a negotiation upon you when you're most stressed. 

• Examples include when one has to purchase funeral services for a loved one or arrange emergency care for a family member.  Many vendors know that in such times cost is not an issue and many won't even ask for (or negotiate) better terms at the risk of appearing crude, cheap or uncaring.  Stress and anxiety might limit one's normal aggressiveness in a negotiation, but it doesn't mean that they are defenseless.   Avoid these negotiating circumstances, if possible, but don't be defenseless.

2.  Another time when people would be wise to defer negotiating is when there is a substantial degree of hostility or anger on either side. The cause or root of the anger is inconsequential.  The reasoning capability along with the ability to analyze proposal is clouded by a hostile state of mind.  It's a lot like trying to communicate with a two year old having a temper tantrum.  Nothing you can say or do will have impact.  You just have to let that moment pass.  I'd even suggest that attempts to 'negotiate' someone else out of being angry are futile.  Clearly this is another battle you don't want to pick.

As in most things -- from purchasing the best apple to finding the right tenant -- selection is the key.  Select the right times to negotiate.  Doing so allows everyone to win.