A physical product might not be the best idea to start with – you have to store the items, order stuff from China (if you're not manufacturing it yourself), invest a great amount of money into it, wait for months until it arrives, realize it doesn't sell properly, aaaand you're done. Gameover.
And don't get me wrong – if you have this sort of "play money" where you just drop $10,000 somewhere and don't worry about whether it's bringing returns – then go ahead, you might as well experiment around!
But most people won't have this kind of "luxury" when they first start out and decide they want to become an entrepreneur. By the way, the same principle applies to virtual products:
You might have an IDEA that YOU think is cool and that you ultimately want to pursue. You may start to create some content, record videos of 40 hour lengths, put it all in a course and tell people about it...
Only to find out that you've developed something completely off the market that nobody really needs, after it's already too late... but hey, at least it's better than doing NOTHING, right?
And despite being driven and ambitious, all of these efforts have one thing in common:
They are trying to shove fancy ideas and concepts down peoples' throats, without ever asking what they REALLY need (it's pretty ego-driven if you ask me.)