There are four kinds of friends you could find in this world. Bridges, tunnels, wells, or grounds.
A bridge is a friend that helps you get over something. A traumatic event, an insecurity, perhaps even temporary loneliness or boredom.
A tunnel is a friend that helps you hide. You hide from your issues, your feelings, your failures.
A well is a friend (if you can even call them that) that ***** you down into their world. Down to a dark place that's hard to escape.
A ground is hard to come by. The ground is a friend that is always there for you. Keeps you level-headed when the world seems to spin too fast.
Don't mix them up even though it may be tricky. Some people shouldn't stay forever, but those that deserve you, appreciate them.