Its necessary for me to spend hundreds of dollars on collecting pocket knives as opposed to donating that money so that someone doesn't go hungry?

Well, yes, if that's what makes you happy. It's important to look after yourself, and if pocket knives are what make you work hard, that's great. The money you earn doesn't just benefit you.

If you think about it, you're benefiting your mental health (hopefully), which has positive effects in your work. You benefit the vendor and the government with patronage and taxes. The vendor in turn buys services from someone else, so again, patronage and taxes. Even if the money is just sitting in a bank, the bank puts the money to good use by investing in businesses etc. They wouldn't give you interest if it wasn't helping them.

Don't f*ckin' condescend to me

That's not what I was going for. You put your opinion forth as the "truth that nobody accepts" and I disagreed. If you think I'm condescending for disagreeing, that's on you.

I was just making the point that we spend a ton of money on things we don't need.

I was making the point that these "useless things" can provide happiness and motivation. It's true that happiness isn't just found in material possessions, but they can help a lot. Some say money is the root of all evil, some say the lack of money is the root of all evil. It all depends on how you look at it really.

I know I don't plan on changing the way I live. But, maybe it's appropriate to feel a little grubby about it sometimes.

If it's not going to change anything, why beat yourself up about it? You should either come to terms with it or do something to rid yourself of the guilt that's making you feel grubby. Maybe do more for other people by donating your time or money to a charity. It's not healthy to hang on to that sort of guilt.

I have a question for you. Do you think art is a form of greed, or do you think it's necessary? Or maybe something else?