No, I haven’t sampled your ex recently (unless her name is Amber) but it is a general rule of life as constant as gravity keeping you on the earth. Your ex isn’t so great or they wouldn’t be your ex.
After ending a relationship with someone it is easy to forget why it ended in the first place and begin to think they weren’t so bad. This false feeling of nostalgia is more likely to creep in if you are not yet dating anyone seriously and if contact with your ex is infrequent so they do not give their negative side a chance to flourish. I attribute a lot of this to short memory, loneliness, and wishful thinking and we are all guilty of it at some point in our lives. When you find yourself in danger of making your past your present flip the script and immediately remember the worst times you encountered with this person. Your ex is your ex for a reason and most times its best to move forward by keeping your past solidly in your rear view mirror.