A nail strengthens just about everything that it penetrates. A nail is tiny. It's as big as your little toe. However, it's stronger than your entire body at times. The trick is that a nail can only provide strength if it is allowed entrance.
What's your nail? What gives you strength?
If you can't answer that question, then you are lost. Everyone needs an external source for strength. You need strength to make it through the bad days. You need it to keep your creative energies flowing. You need it to just wake up some days.
Open up and find your nail.