Messages to guard against

There are some messages that you need to guard against. They are what we call discouraging messages, aimed at discouraging you from doing what you want to do to become the person you want to be.
Here are some discouraging messages:
Don’t try;
You will not succeed;
You will fail;
You cannot do it;
You are not up to it;
Who are you?

The list cannot be exhausted. You certainly know quite a good number of these discouraging messages. If you don’t mind it, please, add to this list.