We often hear or read about life lessons. For some it means all of our trials and tribulations are part of what we agreed to come back and learn. For others it means learn so that they can do it to others before it is done to them and others treat life like a book to read about but not really think about. And so on.
A lesson requires a receptive mind to learn anything from it. If we learn just to be able to parrot it we will soon forget about it after the need is over. Just look at your schooling after exams are finished.
But lessons require one additional key ingredient that is often ignored. One is taught according to their fitness to learn. If we don't bring this requirement to the table we ignore the preliminary lessons and preparation often necessary for success. Be prepared and receptive for learning new things opens up new lessons to be learnt. They are there everyday of our lives.
Attitude can indeed be a critical component.