"Toughness is a broad term. Toughness could be fighting, being physical and running into guys sometimes mental toughness, too. You have to go to hard areas because you have to win battles in front of the net. It's what I've talked about all playoffs, but sometimes mentally in some circumstances, it's just finding that extra gear.
On a personal level I think it's being able to grow that through experience (two playoff rounds this year), so hopefully they translate to better things ahead.