Does cooking oil go bad?

A few years back, EZ made me brownies for our anniversary and they were delicious. The next year for my birthday he made them again and they were awful. We couldn't figure out what it was. Maybe the oil was bad? Maybe he messed up the directions? Who knew. Well as I attempted to make the cake mix cookies that my mom used to make me everyday after Elementary school, I realized the oil had gone bad. I tasted the batter, and yuck! They tasted just like those brownies. It just had an off taste about it. I tried to bake it out of them, but that didn't help. And I knew it wasn't something wrong with the recipe because I've made them millions of times before and never had this problem. So I taste tested the oil and identified that as the yuck factor. Who knows how long my roommates and I have had it in our pantry, something just get forgotten. So yes cooking oil does go bad! I'm so upset though because it was my only box of cake mix and I wasted ingredients and now I don't have any cookies! :'( Guess I'll have to move onto another recipe.