The first step is to generate ideas. The execution of such ideas is what distinguishes good firms from great ones.
You're still in "startup mode" even if you're profitable. Nothing is certain. Ever.
Your circle of friends may change and end up being fellow entrpreneurs, as you'll have common ground and an understanding of the highs and lows, like nobody else.
Competition is necessary. If you have a competitor, or a group of competitors, paying close attention to what they're doing might save you a lot of time learning—especially if they've been around for a long time. They most likely learnt their lessons the hard way, and there's a reason why they do things the way they do them. Take advantage of this.
The amount of time you will spend in front of your computer will make you seek as much time as possible away from any devices.
You will have self-doubt, a lot of it. There might be nights where you can’t sleep and question - “Do I even have it in me?
You're always busy.
Timing is key. Just because something appears to be a good concept does not guarantee that the market is ready for it. If you don't have a lot of money and a lot of time/resilience, think twice about market timing.
That you might not finish up where you thought you'd end up when you started your company. Your intention may be to sell A, but you may end up selling B. Because, after all, that's what the customer wants and what pays the bills.
That you should automate the majority of your business procedures so that you may focus on what matters most to the company's future.
Do not be scared to share your ideas, out of fear that someone might steal it. Maybe they'll share some pearls of knowledge with you that will benefit you in the long term. Maybe they'll be a co-founder, an early investor, or a consumer!
You have to personally excel at selling to get your business off the ground, there is no shortcut, you can’t hide behind your laptop, you have to get out there and talk to people and get them excited about what you do
No amount of reading or guidance will ever be enough to prepare you for the real deal. You will be hit from every angle - numerous times. Continue to work hard and learn from your own (and others') mistakes.
If you aren't absolutely in love with your idea, drop it. You'll be required to invest way too much time and energy to be wasting it on something that doesn't warrant it.
There's a risk of depression. Startup founders wear all the hats and work long hours with little to no help, even if they have a business partner. Find a community of support - that can help with this. It’s not all doom and gloom — but it’s a real risk nobody tells you about.)