Sometimes we start thinking about the fast and we start worrying that we might have done this way or we might have behaved that way. But the time has already elapsed and we can't go back and correct. Now we have no control over that. So forget that and start getting ready for facing the consequences.
Keep your Face to the SunShine
"Life is easier when you enjoy what you do"
Knowledge is power.
Live an interesting life by taking some risk to get the things not under our control to under our control.
No life without Sun
Yes, the gravity and extend of worry can be controlled and in some cases pondering may cross over to worrying which we may have to balance. Worrying as such cannot be, I feel, said to be a negative trait but getting struck in that circle and not making any efforts to come out of it or to find solutions is definitely a negative trait which we must avoid.
Another angle to this thought is that once we stop worrying about things beyond our control, we are by default submitting ourselves to the concept of fate or destiny. While it is true that what must happen will happen, we, as human beings, are tuned to think and take precautionary measures to either overcome or to solve such uncertain instances.
Let me repeat the example by Sankalan in his response above. When we are driving through an unknown road, it is quite natural for us to worry about so many things like the condition of the road, the facilities available etc but that does not mean that we stop driving. That is why I indicated about the level and extent of worry earlier in this response. Worry you must because otherwise you may tend to be careless but your worry must not hamper your logical thought process.
So, as in any other case, worrying is something that cannot be avoided totally but our efforts must be to balance and limit our worries only to the extent to which it is needed and only to those matters with which we are directly or indirectly involved or affected and to channelise our efforts to overcome or skid through such uncertain situations or instances for positive results and our own physical and mental well-being.
“The door to wisdom is knowing yourself." Anonymous