The number one rule is, know that what goes around, comes around. At work, this means that, when someone has done something to you that had a negative impact on your life and it’s out of your control, let it go. Deal with it by letting it go and moving on. Believe that, at some point, that person’s wrongdoing, or perhaps failure to do what he or she should have, will come back and bite him or her in the ass!
Quite often, people blow a lot of time, energy, and effort trying to figure out why things turned out wrong or, moreover, how to get even. It is not important in the grand scheme of things and is a total waste of your time. For example, if you have a colleague who continually does not pull his or her weight, do not let that colleague drag you down. Take the initiative to work around his or her inabilities or resistance and make headway independent of him or her. You did not hire this person, so you are not in the position to reprimand him or her; so, since this situation is out of your control, you deal with it by coming up with an alternate solution.
Once you accept this as fact, it is usually easier to move on and redirect your attention to what is important for you.
Your initiative and stick-to-itiveness will make you stronger and more confident of your abilities, and others will recognize your achievements, as well as the lack of assistance you received from your colleague.