Thinking about your ex less: you realize that you’re no longer thinking of your ex all the time and no longer torturing yourself about what could have been. Even when you do think about your ex from time to time (which is perfectly normal), it doesn’t make you feel sad, angry, hurt, bitter, etc. You may remember the goods times you’ve shared without bursting into tears.
Music: You can listen to music that reminds you of your ex without being an emotional wreck. And not all love songs remind you of your ex anymore.
Pictures: You can look at old pictures of you and your ex with a sort of detachment. Sure, you may still feel a bit sentimental, but you are not bursting into tears thinking about the good old days, and any setback you feel is brief.
Looking for him/her wherever you go: You don’t look into shops, bars, or other places where you ex might be, hoping to run into him/her. If you do run into your ex, though, and your heart races a little, it apparently does not mean that you are not over him/her.