If you are sometimes forgetful about food cooking in the stove or cookies being baked in oven, get yourself a kitchen timer or any form of timer.
These kitchen timers are relatively inexpensive but they could save you from a potential hazardous situation. Imagine if you left the kettle of water boiling or making a pot of stew at the stove and totally forgot about it. It is dangerous as it could result in a fire.

One of my friend’s mother who is staying alone actually burnt a few pots because she left things cooking at the stove and totally forgotten about it. Fortunately it was only the damaged pots and nothing more serious. Note: If you notice an elderly person starting to forget to turn off the stove, it is sign to switch to electric kettle and to stop the person from doing anymore cooking. It could also be an early sign of illness such as dementia so please get the appropriate medical checkup.
Even if you do not have memory issue, sometimes you can be distracted by your kids who need your attention or a phone call. And then you ended up forgetting about your stove where the gas is on.
A neighbor of mine does baking part time for additional income. During festivals, she would be busy baking in the kitchen, sometimes well into midnight to fulfill the orders that comes in. And as the delicious smells of baked cookies fill the air, it would soon be followed by the sounds of a kitchen timer, signifying that the cookies are ready to be taken out of the oven. Why she did not rely on the timer of the oven is because she is baking the cookies in batches where she would take out and put in a fresh tray of cookies.
In that way, she was able to go on to do other things elsewhere and it would prevent her cookies from being burnt.
There is also the generic timers that comes in all shapes and sizes. You can set a timing and it would ring like normal alarm clock once the time is up.

Alternative to kitchen timers:
Okay, if you do not like the use of a timer, then you can do like what my friend does…. by utilizing the timer option on her mobile phone as a timer. But one must be very diligent and remember to set on the timer…..without getting distracted by other apps on the phone (like an incoming message or Facebook notification).