If you don't do it, how in the world will you learn how to do it.
But Glaser mentioned " We do GT everyday but we never know that it is GT". For example, you are planning to go to Kuala Lumpur (KL) city from UPM Serdang. But then you see the cumulus nimbus developing fast and hanging above the city. You cancel your plan to KL but head for Seremban. Why do you change your original plan to KL city? Because you know from your experience that the traffic will be congested when it rains in KL. Now, you can actually predict what will happen. That's GT.
I call this "Rain Theory in KL" .... mmmmm.