Even cats need to learn lessons in life - we have two cats and neither of them has gotten this one quite right just yet. We have one who comes for short visits involving being patted briefly and on her terms - then a quick exit back into her own space, and the other who gets patted but the more pats she gets the more pats she wants - it's more, and more, and more until we are so over it all, we send her on her way posthaste.
I think there is a fine line somewhere between these two extremes. Nobody wants to be used up and then discarded once affection has been given, and nobody wants to be loved to death and suffocated by affection (well nobody I know anyway).
Life is all about balance - holding on and letting go - giving and receiving love, but not constantly draining others because we haven't developed enough self esteem to be able to manage life on our own without constant affirmations. We all have moments in our lives where we need extra affection or attention, but if it becomes our "norm" then we really need to take a long look at ourselves and find out what is wrong.
The perfect cat comes and sits on your lap in a warm ball, accepts a stroke or two and purrs to acknowledge the relationship. This is the life lesson we need to take from our feline friends - show love, receive love, but have enough autonomy and self respect to not depend on another person to have to constantly pat you and give you attention.