Am I just being selfish?

Ever since I was about eight years old, I have wanted to build a model train layout. Life had different plans. When I had the money, I didn’t have the time, and when I had the time, I didn’t have the money. Now that I’m 67 years old and retried, I have both the money and the time, but it just feels selfish to spend money on something as trivial as a model train layout. There are so many people who could use an extra buck, or who are homeless, or out of a job.

Help me work this out, please.