When are supposed "to know"?

I was just wondering. There is something about American culture where we ask kids, often times when they are children-"What do you want to be when you grow up?" As a high school teacher, I see teachers asking their students what their major will be in college leading these students to really think about what they want to do with their lives. I personally think that this is the biggest mistake that you could do to a college bound high school student. I mean how is a 17 year old kid supposed to figure out what they are going to do with their life? I have friends who are ranging from the ages of 24-34 who still don't know what they want to do with themselves.

So what ends up happening is these kids go to college and all their minds are on is what they are going to "become". Never leaving their minds on the present moment. Never taking college for what it should be in my opinion-which is an opportunity to learn! So we end up with economics majors or pre-law or pre-med majors. The common question being asked to someone who revelas their major is- "So what are you going to do with that?"

Maybe it's just this capitalistic regime that we are in. But college for me was so much about potential job opportunities as opposed to actual learning and upliftment through knowledge. And so 2 changed majors, 5 years, and about $40,000 later I graduated with a degree in Religious Studies. And no... I am not a priest or anything like that. But I have to say I enjoyed the remainder of college when I was actually learning something. And this brings me to my post question. When are we supposed "to know" what we want to do or what we want to become.

I am asking because for about the past 8 years of my life I have known that I wanted to be a teacher. But high school teaching has become an embarked journey that has left me knowing that this is not what I want to do for the rest of my life. So I'm just wondering because the question of this post is the burning question that my self and almost all of my friends are yearning to answer. And I figured that after 28 years of breath in this existence, I would have more of a clue. But many days, I feel like I am back at square on trying to answer the very same question of-"What do you want to become when you grow up?"

Shit... It feels crazy because I have to answer this question again, but I'm all grown up now. So maybe I should panic. Or maybe I should just not care and let things fall where they may. I know the answer lies in between both of these extremities. But I just thought i would know by now.