What have you packed for lunch?
Some things that might help:
-How much time are you going to spend standing in line getting that meatball sub? Wouldn't it be nicer to just take your lunch outside and enjoy a few minutes of fresh air instead?
-How are you going to feel after eating it? I find with a lot of restaurant food, I feel kind of yuck afterwards. And really, you spend what, MAYBE 15 minutes eating it? 15 minutes of eating vs. an afternoon of feeling sluggish. Hmmmm.
-Is it really going to taste as good as you imagine? I know I have this problem with baked goods....they seem like they are going to taste amazing and....usually they're just good or even kind of meh, which is a let down. Total waste of money and calories.
-Food waste is actually a substantial contributor to global warming! Plus all the packaging, etc. involved with takeout. Do something nice for your future self and eat the food you already have.