What if there are other activities that OP considers more valuable and rewarding? Spending time with friends or family? Starting a new business? Working on that

What if there are other activities that OP considers more valuable and rewarding? Spending time with friends or family? Starting a new business? Working on that programming project? Learning how to play an instrument? Exercising? Meditating? Cooking? I'm not sure such a blanket statement is helpful. This isn't just about money, it's about opportunity cost. The time that he sinks into mending that Tshirt is time he could have put into any other potentially more worthy endeavor.