Okay, there is something to be said about trial and error. I love to try new things out and see how it goes. Sometimes that means realizing something doesn't quite work out the way I planned. Hopefully I learn from this and can make it better next time.
When it comes to organizing for example, paying close attention to the words "removable" and "permanent" is important when using adhesives. I've found this to be true of labels for file folders and for clear mounting squares that are used to post paper. If you want your labels to stick, don't use the removable type. They'll peal off and frustrate you every time you open your filing cabinet drawer. Use the permanent ones. If you need to re-label it, just put another label over top. As far as the mounting squares, sometimes the removable won't hold a poster or item up properly. If the paper has a tendency to curl, it may peal off the door or surface you'd like to mount to. It may also be the actual surface you are mounting it to. Is it uneven?, too rough?, etc. In this case, you may need to move to plan "b" and change the location of the item, like moving it to a magnetic surface like a fridge or file cabinet and use a magnet instead.
My advice, don't give up. Trial and error is how we figure the best solutions out. If you want something posted somewhere and it doesn't want to stick, consider a different option. Problem solve a little at a time until you get the result your looking for. When you do, smile. Mission accomplished.