Above all, don't fear difficult moments. The best comes from them.
Considering the source--Levi Montalcini, a 100-year old Nobel prize winner--this quotation seems meaningful, and not in hokey or sentimental or Hollywood-blockbuster sort of way.
Someone I'm close to has been considering the nature of achievement, and failure. I think this: if you're not failing, it means you're not trying.