Bravely Go Where No one Has Gone Before

I like someone I recently read attributed to David Bowie.  Like many of the quotes I read of various ones I am not necessarily into their music but I do nod my head in agreement with some of the things they may say.
"If you feel safe in the area that you’re working in, you’re not working in the right area. Always go a little further into the water than you feel you’re capable of being in. Go a little bit out of your depth, and when you don’t feel that your feet are quite touching the bottom, you’re just about in the right place to do something exciting."
By safe place I do not think he is talking about the environment work is carried out.  I am all for feeling I am in a safe place when it comes to the security of the working environment.  I feel safe places help to avoid distractions.
What I think he is talking about and what I agree with is avoiding “familiarity breeds contempt.’  In my mind it is ok to enjoy for a time having gone out of my depth and known success.
To me it is like enjoying a meal after having spent time doing something unfamiliar that succeeded.  I need it.  It does me good.  It prepares me better for the next phase.  But it is not an end in itself.
It is like someone who says they have 20 years’ experience.  Was it one year 20 times or 20 years of growth?  It is like musicians that produce an album.  So often reviewers are noting if they have broken new ground with the music or the latest album is the previous album with new songs.
That highlights to me the danger of success.  It is so easy to stop growing and rest on my laurels.  It seems so often the greatest impediment to future success is past success.
My motto in recent times is “saving the best till last.”  Maybe I went out of my depth and experienced some success.  To me that is a foretaste rather than a place to set up camp.  There is more for me to go get.  I may not be able to touch the ground and it may mean like the star trek theme “bravely going where no one has gone before.”  Yet to me excitement lies in the unfamiliar.