Joel pointed me to two blog posts on this topic which seem worth adding to the discussion: Steady yourself, those world-changing thoughts are not productive and Start something small.
Quoting a few passages from the first:
It may be healthy to be ambitious, but often these thoughts occupy more time than they should and stop us doing the real work we need to do to get anywhere near to those thoughts becoming reality.
It is easy to look at the success stories of the world and think they started at the top. Let's try and question that and think how all successful ventures or entrepreneurs started with something small.
And the second:
What I'm starting to notice more and more, is that great things almost always start small. Most of us know that Branson started the Virgin brand with a student magazine, but Virgin is just one of many examples which shows that the reality is counterintuitive: actually, the best things we know and love started as tiny things.
I've found that if I look into my own life, I find similarly that some of the most important achievements I've made started as little projects. My startup Buffer itself is a great example: it started as a two page website and in addition the short blog post describing this process has now turned into a talk I've given more than 30 times.
This is more evidence that thinking small is an essential first step before you start thinking big, which opposes the usual Silicon Valley advice of thinking big and choosing ambitious startup ideas.
Why is this idea so prevalent if it leads to lesser chances of success? One theory would be that most of the "think big" advice comes from investors (directly, or indirectly via entrepreneurs they've funded). Typical investors definitely wants all their investments to think big - that's how they make their returns.
That doesn't mean it's good advice for you.
Instead: Think small, make it work, and then think big.
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