What does my husband mean by this?

We have been happily married 15 yrs...We have always had a routine but satisfying life and i never get bored with it and we make love 2-3 times a week..A few times only out of curiousity and not cause i thought he was bored with our life i asked him if he ever got bored with our life and wanted to try something new and different and he has always said "no i like the way things are"...He is 41 and im 37...So what does he mean by this?