I sometimes forget little things - is this natural or is it something more?

Forgetting little things is quite natural and common. It is an executive function, so those who have ADHD have issues with short term memory more than those who do not have a condition that affects executive functions. If the memory lapses cause significant issues in your life you may want to discuss it with a doctor, mental health specialist, or coach to help you determine the cause and help you develop adaptations and tools that ill help you cope and improve your memory. Tools such as to-do lists and to-do apps as well as memory-enhancing exercises can greatly improve one's day to day life. Simple steps like writing things down and using alarms and reminders can help tremendously. What works for each individual person will vary and can take quite a bit of trial and error but is worth it, in the long run, to continue to experiment until you find tricks, tips, and life hacks that work for you.