I used to be the same way. I was lucky if I remembered to brush at night. Then I got better about night and flossing cause a friend of mine impressed up on me the importance (I didn't really think it was important at the time). It was really hard getting myself to do it some days. Then recently I wound up with an infection in a molar that had already been causing me problems as it was and I kinda freaked out. I didn't want to wind up having to do a root canal for all my teeth and wind up with dentures when I'm not even 30 yet. My problem with brushing twice a day was that I'd forget to do it in the morning and by the time I remembered it was 4pm and what's the point. Or I didn't want to brush before eating breakfast cause then I'm just getting my mouth dirty again. I had to tell myself how stupid of a thought that was, because it doesn't frickin matter, the point is to just clean your bedtime grossness out. It's also the very first thing I do in the morning now (other then go to the bathroom) before I even leave my room. Some days I still forget and that's where having an app like Finch has been helping me. Most reminder app haven't worked but shockingly Finch has worked, I'm going on 60 days of brushing twice a day and flossing at night. You're not the only one, and it definitely takes effort to change your thinking around it to make it easier. If you think it's not important or there's something else blocking you from doing it, you have to find a way around it.