That's probably true, but I think this bears the danger of expecting happyness to come from a few short-lived moments in time. As long as you haven't reached the goal, you won't be satisfied because you expect the satisfaction to come from a future event. And as soon as you've reached the goal, that source of joy is nothing but a memory of the past, and the memory will rather make you sad because you'll wish to repeat the feeling.

I think that's why it's the eastern wisdom of "the path is the reward" bears a lot of truth. It's nice to reach goals, but to maximize joy/happiness it's much more important to enjoy the path that you take, because that's where you'll spend 99% of the time.

Constantly thinking about consequences, the future, or the past is sick? That doesn't make sense.

Anyhow, no, we aren't all sick in the head because we think a lot. We think a lot because it is possible. We have a brain for a reason, and that reason is to use it. (Hopefully I didn't mis-understand your OP.)

Not that thinking makes us sick but that we are never thinking about present time is what makes us sick I think is what Tolle was saying.  People can interpret it different though im sure

Oh, I'm sure people think about the present. But when you think about the present, you must think about the future too. Ex:

"Should I eat these fries?... They look so good... but they will make my butt bigger!" Not the best example, but that's what I mean.