Daily Learning

Question

I saw the post and reply about Shnaim Mikrah and was intrigued by the fact that every Jewish male is obligated to read the perasha twice each week (and targum once). What is the extent of our daily obligation to learn Torah? Is it really true that we are obligated to learn Torah every moment, and that the only reasons that we do not is the fact that we have bodily needs to fulfill (like eating and feeding our children)? Or are we only obligated to learn Torah when we have time? (If we don't make the time, will there really be time?) Thank you for all of your support.