This is one of my most favourite thoughts and in life I feel that keeping in touch with this thought, helps me understand that as I stretch myself and continue to grow, well, sometimes things can get uncomfortable...and that's ok. I'm becoming a bigger better version of me.
Feeling uncomfortable means growth to me. It means being outside of any given comfort zone, and 'feeling around in the dark'. At times you mighten know what you are doing, or know the outcome, and it's all so akward, however you do know your feelings. You do know the whisper of your heart and you also know that following it is the key to your personal happiness.
So be brave, take your leap, follow your feelings and be ok with feeling uncomfortable, because it's in these times of uncertaintly we grow.