Not from brainstorming. From personal pain, professional experience, and things that just changed.
The reliable sources, roughly in order of how well they work:
Personal pain — a problem you have yourself Professional experience — a problem you saw repeatedly at work A recent change — new technology, a regulation, a cost that collapsed, a behaviour that shifted An underserved group — people every existing product ignores Boring industries — large, unglamorous sectors running on spreadsheets and phone calls
What these share is unfair access: you know something most people do not.
Because ideas generated by brainstorming tend to be ones anyone could have had, in markets you do not understand, for customers you cannot reach.
Founder-market fit is not a slogan. If you spent six years in logistics, you can get twenty logistics managers on the phone next week. Someone without that background needs six months just to reach them.
Personal pain — you kept missing invoice deadlines as a freelancer, so you built a tracker. You are the customer, so you know exactly what matters.
Professional experience — you ran ops at a hospital and watched nurses spend forty minutes a shift on a rota. You know the workflow, the budget cycle and who signs.
A recent change — speech-to-text got cheap and accurate enough in 2024 to transcribe consultations in real time. That was not possible in 2020, and 'why now' answers itself.
Boring industry — waste management scheduling. Nobody at a hackathon builds this. The companies are large, the software is dreadful and the buyers are reachable.
The common thread: each founder starts with an advantage nobody can copy quickly.
First-time founders often chase ideas in fashionable spaces where they have no advantage — the market with the most competitors and the least insight available to them.
The other mistake is dismissing a real problem because it seems too small or too dull. Boring problems in large industries are among the best startup opportunities precisely because so few founders want them.
Twenty of them, no filtering. Annoyances, workarounds, things you complained about this month.
Which of these involve people you can already reach, or knowledge most founders lack?
New capability, new regulation, new cost curve, new behaviour. 'Why now' is an investor question and a real one.
Groups every product treats as an afterthought are often underserved rather than uninteresting.
Can you get ten of these customers on a call this month? If not, the idea is much harder regardless of how good it is.
At the beginning, or when the current idea has clearly failed validation and you are looking again.
Do not keep generating ideas as a substitute for testing one. At some point the list is long enough and the constraint is validation, not inspiration.
Apply this to your own startup in My Full Journey (free account).