ELI5 - is time real and if it is how?

Is there any actual quantifiable way to measure time other than using your memory and saying "time" passed? Because from how I see it, it's just a human made concept. The only thing that makes time measurable or observable. Is you remembering the states of events and how they changed. That's what all time is. The concept of change and history strung together. change in say like, An atom moved from point A to point C. and history in like how at one point it was at points A, B, and C. Combined, you have time. But is this really a real, tangible thing or law? or just one of those illusions the brain makes to basically simulate reality.