I've got this! The power of self suggestion.
Do you find yourself regularly saying things like...?
"I can't remember anything"
"I'm useless at this"
"I don't think this is going to work"
A good way to tackle this is to ask yourself to assume you can do it. Most people surprise themselves when they try this. Here are some examples of how to handle this:
"I can't remember anything" - "If I could remember something, what would it be"?
"I'm useless at this" - "If I were good at this how would that look?"
"I don't think this is going to work" - "If it did work how would that make me feel?"
This technique is useful for overcoming low confidence and resistance as you are not directly demanding something of yourself - rather enquiring politely :)