I can, therefore I am.

The most effective way to do it, is to do it.

If you think you can do it, you can.

It's always too early to quit.

To know oneself, one should assert oneself.

Things do not happen. Things are made to happen.

What you do today can improve all your tomorrows.

Go for it now. The future is promised to no one.

The wise does at once what the fool does at last.