Why did Gandalf let go and fall off the cliff?

Meleph-whatever and anyone else who saw my now deleted, last, and most embarassing post may I offer my most sincere apologies. I have had just had THE worst last few weeks of my life and everything I perceive seems to come accross as an "everyone is out to get me" sort of thing and I totally took your comments the wrong way Mel. I would like to confess to my total shame that I sent Mel a private and not so nice message also. Please can I just start afresh and say hello everyone nice to meet you all and I look forward to being dead and posting intelligent thoughts questions and comments in the future