Hey, I'm gonna go ahead and deviate from the rest of the group here - depending on what field you work in and what your job is, you might not be taken as seriously as a worker if you're seen eating children's food at your desk. Sure, you might get a few friendly comments off of it like, "Oh! I used to love those! Man, those memories...." or, "Oh! I always liked that kind with the ham and the fun size snickers!" But when it comes to things like being taken seriously for a big promotion or to be given responsibilities like handling big accounts, they might want to avoid putting the guy who dines on Lunchables with a serious client. And yes, I know you wouldn't take them out for lunchables if you're trying to make a serious pitch of some sort to them or having some sort of other meeting, but that image of you eating kids' food is going to stick around in their minds when they think about who to give which responsibilities to.