The drive you need to accomplish whatever you're attempting—big or small—needs fuel. Instead of letting slip-ups set you back, psychologist and author John Norcross recommends you make them the fuel: 

"If you are learning to play the piano, you don't give up because you miss a note. It's not whether you slip, it's how you respond to the slip."

 Cut yourself some slack and remember that things take time and hard work. Listen to the sound of your "missed note" and let that push you forward. You missed that note yesterday, but that doesn't mean you'll miss it today. via "If You're Learning Piano, You Don't Give Up Because You Miss a Note".