When required to learn or practice something we don't really enjoy, we often ask "When am I ever going to use this in real life?". The question is somewhat rhetorical in that we have already likely judged the activity as useless and expect an answer that will justify that position. However, even if the answer to that question is "You won't", the process of education and the topic itself are still very useful. Why?
Consider exercise, particularly strength training: push-ups, pull-ups, squats, bench press, you name it. When will you be asked to perform any of these activities in the course of a "real life" activity or job? You won't. However, these exercises will make you strong and prepare you to better perform real life activities like lifting objects, climbing, walking, or even just sitting up straight. That is why they are useful.
Now consider education. When will you have to use truth tables in "real life"? When will you have to write term papers? When will you have to recite a list of US Presidents, or world capitals? You might come up with answers for some fringe jobs or tasks, but for most people the answer is "You won't". However, education makes your mind strong and prepares you to better perform real life activities of every type. That is why it is useful.
Education is like mental exercise. The more of it you can get on a regular basis, the better.