Melancholy

I had a bittersweet day of work today. As I mentioned earlier there is a possibility that I am on track to get a promotion and it seems my facility is already congratulating me. Unfortunately, I had to let a worker go that was very helpful for the last year during a transition phase at my company. The worker was a temp and happened to take a vacation a few weeks ago. During the person's time off we filled the position with another temp and realized this temp was better suited for the job. The person returned from vacation but we were able to keep both temps for a period of time. This week I was told we could only keep one and I with the help of others came to a conclusion to keep the replacement temp. I understand it was a decision that was better for the company but the guy I let go was extremely nice so it was a difficult decision. Its been on my mind since I left work so I had to say something. I can't help but to feel guilty that I could have had such a good day while this guy was less fortunate. I guess it would be a moot point if the guy wasn't nice. Has anybody ever experienced this?