I recently had an experience, and I had to really check myself.  I invited a couple of friends on a trip, and since I had extra space, it didn't cost me anything, and they were able to go for free.  There are times when I do things without the expectation of anything in return. Usually when I invite a travelling companion along for a trip, I have no expectations...I'm inviting them because in all candor, I really don't like doing anything alone. Although, I'm pretty much a loner, I like doing activities, fishing, hiking, snow skiing, gambling, and sex with others, ergo...Temptation Tuesday.  So, actually on almost all trips except for with family, my companions are in the truest since...escorts...people who are coming along just to keep me company without any further expectation.  

However, this last trip, I found myself having an "expectation".  The expectation was that if my travelling companion came across something fun, they would invite me, like I had invited them.  Therefore, I had set myself up for disappointment. The day after I returned from my trip, my travelling companion proceeded to get invited to a series of parties and outings.  They did not invite me, or even tell me they were invited.  With most people this doesn't bother me...what someone does when I'm not around is their own business. But for some reason, this person not even thinking to invite me the next day after we returned from a trip, really got to me.

Lesson learned....either pick your travelling companions better, or make sure you only travel with people who you are ok with "out of site, out of mind".