In English we have the saying: "it is better to have loved and lost than never to have loved at all." Or to put it another way; if you never try to do something, although you can never fail, you will also never succeed. And to complete the trinity of sayings (!): "To travel hopefully is a better thing than to arrive." -- i.e. the journey and the experiences are often better than the destination. So I say (within reason): Act!

You earn your experience. At least you tried. There are many people who want to change themselves, they have many ideas,a lot of plans but at the end they just do noting.

You're right, in some cases is very sad, for example, if I want to go to foreing conutries in order to change my life and some weeks or months or even years later I am forced to come back in my country and return to work at the same place with the same people, it means that all the path or my determination it's been useless? I hope to be clear, if you know what I mean.

Sorry I am not sure what you mean? In what situation do you mean to ask if we should act or not? It depends on the circumstances.