About 12 stories below my apartment is a rooftop that apparently has been planted with grass. It's a nice look really albeit a bit overkill. Today however, I watched a guy weeding the roof.  No joke, he was out there for a few hours, plucking weeds from the grass roof.  Keep in mind, this is eight stories up from the street.  It just reminded me that weeds will literally grow anywhere fertile (and even in places that may not seem feritle at first glance - the roof is covered in crushed stone - no soil that's visable).  Persistent suckers.  It's no different with your mind - if you don't take the time to "weed" and cultiave the type of thights you want to develop, something will fill that gap.  It's not a matter of whether your mind will develop thoughts and habits.  It's a matter of what type of growth you want.  If you don't choose and influence a direction for your thoughts, the world around you will.  Think of your mind as a garden, and make the conscious choice as to what you plant there.  The sooner you do it, the less "weeding" you'll have to do.  Happy gardening.