It's easy to see a specific tool or solution as being for a specific function and nothing else. This leads us to dismiss solutions because we believe they're not "for" the purpose we need them for.
Many inventions came about because someone used an object from one domain for another purpose, and created something new in the process. If you want to come up with as many ideas as possible, it's important to train yourself to consider all sorts of tools and approaches, even if they're not traditionally used for the problem you're trying to solve.
The most famous example of this problem is the "Candle problem":
The test presents the participant with the following task: how to fix and light a candle on a wall (a cork board) in a way so the candle wax won't drip onto the table below. To do so, one may only use the following along with the candle: a book of matches, and a box of thumbtacks.
The most efficient solution is to empty the box of thumbtacks, use the thumbtacks to nail the box to the wall, put the candle into the box, and light the candle with the match. The concept of functional fixedness predicts that the participant will only see the box as a device to hold the thumbtacks and not immediately perceive it as a separate and functional component available to be used in solving the task.
It's not easy to suddenly start considering everything for its potential to solve any given problem. It's a muscle that you need to train. But if you do, you'll be able to consider many more possible solutions.