Saints are not perfect. They aren't sinless. They make mistakes, but they seek forgiveness. St. Jerome was said to be quite grouchy. St. Therese of Lisieux often fell asleep in chapel during prayers (and who wouldn't at 3 a.m.??) St. Philip Neri was a jokester, and I imagine that irritated some who thought only boring piety was allowed for a priest. Padre Pio chased some poor woman out of the confessional - yikes!
For us poor humans, there is no such thing as perfection. We are going to keep messing up, but we also must keep inching closer and closer to sanctity. Admittedly, for most of us, it is two steps forward and three back on some days, and we can't see the finish line. There is no excuse for sin, though, and we must reapply ourselves daily to live out faith, hope and charity every moment. We strive not for perfection (because only God is perfect) but for holiness.