Also, you may want to look at this:

You say you have this house since 15 years. This new tenant is in his 20's.
So, you were a property owner already, when he was still feeding at mom's and dad's fridge.

What I am trying to say is, he doesn't even have as much experience renting a place, as you have owning property.

Let him get a few years older, make his experience, buying or renting, it doesn't matter.
What will teach him, is the one situation that puts him through the grinder ... after that he will act accordingly.
Ofcourse, provided he learns. Some never learn.

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