Find a problem in your own life that you have and work to solve it. For example, when I was in college, I found that I was spending A LOT of time trying to find a good deal on textbooks and still paying A LOT for them. I would search on Google for the books I needed and then opened 10 different tabs (Amazon, Bookrenter.com, etc) to find which site had it at the cheapest price. The textbook price comparison site, book.ly made that process easier by aggregating the prices of my textbooks all on one site. When you solve a problem that you have, you are a customer of your own product - which makes it easier to know what your users will need/want and what will make for a better user experience.
Ideas come from your own life experience, yes -- but they also come from things you're passionate about. For your startup to be successful, it has to be built around something you care about deeply. Otherwise you won't be excited enough about it to get anyone else excited about it too. And if you can't get other people excited about what you're trying to do, it's probably not going to happen.
Being an entrepreneur is an exciting adventure. Passion, hard work, patience, and a desire for lifelong learning are key. Firstly, I found I had a passion for helping those in the education industry, then it was validated by my drive to succeed more & more in this field. Lastly, I "listened" to what customers were asking for and continually never able to find. As a result I developed my organization based on what was missing in the market to help educators.
Give yourself time, try different things, and explore - listen and ask lots of questions among peers and mentors. You'll find your niche and then an idea. If your first idea is not on track keep trying until you find something that sticks for you and prospects. Good luck!
Ideas come from life experiences. Most of the cool startup ideas come out of people trying to get somewhere or do something and realizing there could be a better solution. Also, running books on entrepreneurs can be helpful. Good luck. :)
Don't force it upon yourself. Look around your environment and see how things can be improved.
Here's an example of my train of thought when I think of ideas.
Too many people are eating unhealthy burgers at McDonald's and should be eating healthier. That's a problem and I should investigate the market and see how many people WANT to eat healthier. If there's enough of a market, maybe I should create the World's Healthiest Restaurant.
Initially your ideas will sound stupid (like mine above), but after iterating through the ideas and investigating how to improve those ideas, you'll start to see how the pieces come together.