Teach Me How To Draw Again

I don' know if it's just the lack of practice or I'm just too lazy and insecure, but it seems like I don't know how to draw anymore. After a childhood of doodling, sketching, painting, and art contests, it shocks to me to say that I don't know how to draw that well anymore. And it sucks because I'm currently taking up BS Architecture. I draw landscapes and buildings but cartoons, portraits, people... *Sigh* What's wrong with me?