I left my husband, and now he thinks I am in mid life

I left my husband 10 months ago after 17 years of marriage, I would have left sooner but didnt because of our children or ability to financially support myself, We discussed the separation and he was aware I was leaving months before I actually did, we hadnt slept in the same bed in three years and fought all the time, I am now involved seriously with someone, and my ex feels I am going through a midlife which I am sure I am not.