Imagine starting to jog on a treadmill... a light, easy jog that allows you to carry on a conversation with your fellow jogger. That's the beginning of career for you. You may work the whole day, but you can definitely chat with others around you and not fall too far behind. You can always catch up.
Somewhere down the line, the treadmill tilts... you are now jogging on an incline - a rise in career. You jog faster, labour more to cover the same distance. Your work has become intense and takes more resources out of you. Some one hands you juggling balls... four juggling balls, your family, your friends, your own interests and hobbies and your health. You juggle these while the treadmill tilts more and more... as if that was not enough, someone yanks up the speed on the treadmill...! Not only is your work tougher, you also have deadlines (and sometimes insane ones).
As you move on in life, the pace just keeps increasing and the slope gets steeper... more juggling balls get added to your life... that's today's world for you!