We all are in countinous learning phase in life. Day to day we are learning new things,new language words,new faces,new gazets by all means of modes like reading books,newspapers,watching TV,movies,meeting different persons etc.
We learn more effectively if thats visual to us, someone guide us for 'how to do' in person. Like our parents teach us in childhood by doing theirself.
We are receiving knowledge through all activities whether its completely new one like river rafting or the usual one like brushing your teeth.
But i would like to make point ,the thing which we do personally will have more impact on us.As we would be experiencing the situation in real. If the things done in real situation ,as they said,it will stored in uncontious mind which is useful in time constraint situation.
Self learning is usefull ut we will not be sure if we are not correct path.So the trainer is indeed ,and if its personal then its icing on the cake. :)