The key is to unlock your creativity again. Try letting your inner child out. Their intuition and imagination guide children. Don't be afraid to make mistakes. I dare say he failed many times before he got it right.
People learn through trial and error.
Write your ideas down. Ideas can come to us at the oddest times in the most awkward of places. Most of my ideas occur to me as I am on the brink of sleep. Therefore, I keep a notebook beside my bed and write my ideas down, then when I am a bit more awake, I review my ideas. Keep a few notebooks easily accessible throughout the house so that you can write down your idea as soon as you get it.