An ADHD brain is like an on/off switch. Instead of fine-tuning levels, it tends to be all or nothing—hyperfocused or completely distracted, overwhelmed by emotions or detached, full of energy or exhausted. This inability to modulate different mental functions at the right levels for the situation is what makes ADHD a disorder of regulation.

In my 40th year, I never expected to discover—for the first time—that I have ADHD. My story is like so many others: a parent starts noticing something about their child, dives into research, and along the way, realizes that the very thing they’re investigating also applies to them. Here are just 7 of the things about ADHD that blew my mind.