Your mind is a lot like a garden. If you're not careful with what you're feeding it with, you'll be forever working on removing the weeds.
You must always feed your mind with positive, uplifting messages.
You need to be conscious on what you plant, avoid negative inputs and focus on growth. That way, your mind can fully flourish.
Every time I've felt down, plagued with self-doubt or know my fears are creeping in (happens to everyone) I fuel my mind with positive inputs.
At the loudest volume I use Youtube clips of Les Brown, Tony Robbins, Robin Sharma, Dr DeMartini, and other inspirational clips to flick the switch.
I've even recorded my own voice sharing affirmations and positive messages which I'll listen to sometimes in order to spring me back into place.
As humans, we are much more conditioned to feel negativity and experience doubt as opposed to maximising our potential and dreaming bigger.
The question you need to ask is: Am I fuelling my mind with rubbish and forever pulling weeds? Or am I caring for my mind like the wonderful garden of growth it is?