Glue

Sometimes glue must be thick. If not, the papers won't stick together. If they don't stick together, they are easily torn apart. If they are easily torn apart, they are useless. If they are useless, then why the glue and the paper in the first place?

On the other hand, if the glue is too thick, the papers might never come apart again. Then what are you going to do if you want to use the papers individually again or stick them with other papers? Even if you do manage to rip them apart, the paper will be torn and never be the same again.

But if the glue is too thin, then thing won't work out either. The papers will come apart and be sticky and damp. Then it will smear your hands, your table, or anywhere else that you put the them on. Then you will get annoyed and irritated and just forsake the whole thing.

So the best way? Make the glue not too thick or thin... It's hard, but might, just might be workable... :)