"Before Anna, I'd had a few relationships and I'm glad I've been around a bit. I know where it's gone wrong or know who are the wrong people for me and who I might be wrong for"

This quote by David Thewlis suggests that he has actually gained from his previous relationships and has actually acquired a better understanding of himself and what he desires in a partner. He is grateful for the experiences he has actually had, as they have enabled him to recognize the incorrect people for him and the incorrect individuals he might be for. This implies that he has grown and grown from his previous relationships, and is now much better geared up to make better decisions when it comes to relationships. He is likewise knowledgeable about his own flaws and drawbacks, and is willing to accept them and deal with them. This quote is a testimony to the value of learning from our past experiences and utilizing them to make much better choices in the future.