But you have to understand a couple of things. I'm the eldest of six. Both of my parents lived through the Depression and I was really not that far removed from it myself. Additionally my father grew up as a semi-orphan on NY's lower east side just before and after WW-I. All of that equates to a household where the watchword was to never waste, and always save, and use something for as long as it could be or to pass it along to the next in line if it had been outgrown.
I am a thing saver. I'm not as bad as my parents, and I will spend money if I have it, but yes I do tend to accumulate. It's not that I find it difficult to give stuff or throw stuff away, it's more that often the thought never even occurs. If it is still usable, why get rid of it, especially if it will be replaced? You can see where this goes.
The other side of it is that even giving stuff away isn't always easy because I want to be sure that it will still be used by someone. In the case of the shirts, I refuse to just place them, or almost any clothing, in a common collection bin. In too many cases, content there is shredded and sold as fiber, or used for rags, instead of being used as clothing by someone in need. So I'll have to hunt up a charity that is actually a charity. It can be done, but it will take a bit more work and time.
..... but, I just wouldn't feel right doing it any other way.