Remember this always - "Entrepreneurs bring value to an idea."
One of the most common types of startup businesses is when someone decides they want to make their hobby into a business.
But let's be clear here. Not all hobbies translate well into a business that creates an income. I always advise fledgling entrepreneurs to follow their "interests", which may not exactly be a hobby.
For instance, if my hobby was collecting sewing thimbles or drink shot glasses from all over the world - that may make for an interesting hobby but it's doubtful I could get anyone to invest in it.
The great thing about business principals is that you can apply the same questions to a bootstrapped startup as you can a major startup funded by $10 million from a venture capitalist.
Ultimately, who is your customer? How do you acquire/market to those identified customers? What is your profit on each unit or service sold? Do you have enough capital to sustain the business? What makes your business unique or why would someone buy your product or service as opposed to your competitors?
Few people have hobbies they can convert to a stream of money, but more people can turn their "interests" into businesses. For me, telecom technology was not a hobby but it definitely was a business interest.
If you have an interest or hobby you believe can be turned into a business, ask yourself the questions posed in the preceding paragraphs. If you can articulate clearly how turning this hobby or interest into a profitable business, then you have a plan.
Many people use their business interests so they make enough money to pursue their hobbies. The business interest was a means to end, to pursue traveling or collector rare cars, etc.
If you believe you have a hobby that would translate into a business, then go for it!
Never lose sight of the fact that your dreams of pursuing your own business are yours - and do not be sidetracked by detractors, provided you have a well-thought out business plan and the perseverance to see it through!