what would you tell them. Me, I have been maintaining since Sept or Oct 2017 so this is the viewpoint from only about 19 or 20 months in. Others who are just starting or are longer down the road may have different ideas so please share length of time in maintenance and your one BIG takeaway if you have one.
I would say for my share that maintenance is not a stagnant stable process. It is an every changing thing which I have to watch for trends and take action on. Whether it's weight, energy, workouts, fitness, health. It's a more long term view but it's not something which hey - here we are - now we do this forever. And actually I sort of like that about it. I can experiment with different things/ideas/goals over a month or longer and see how my body and brain react.