I see this a lot but I feel its quite difficult to actually pull off. Even though your mvp can and should be shitty sometimes it still takes a lot of effort and talking with potential customers to even figure out what you should be building, and its extremely difficult to do when your still trying to work a full time job. Maybe someone who has actually done this before can offer their perspective
It resonates with me a lot. I have this idea I would like to test. But once I'm done with my work (I'm a PM under french lockdown, I spend my whole day in front of my computer), I really need to disconnect, spend time with my 3 kids and wife, or exercise.
I'm afraid that if I spend my evening and nights into trying my idea, I would either 1/ not get results fast enough and hence loose faith in the project or 2/ get burned out and hence disgusted by the project.
Or maybe it's just the lies I like to tell myself to be comfortable with keeping on procrastinating this...
I also was thinking like you but at the end I understood that I shouldn't have huge expectations. I decided that I just need 1h each day for implementing MVPs. After 3 months, I get used to this and can't imagine day without this hour.
I'm in a similar situation, although with only 1 kid yet. I think you're spot on that building a working prototype in your free time will be either slow or exhausting.
But most of this start-up advice seems to be geared at single college students, and they'll have enough free time to pull it off.
This trade-off doesn't go away when you start a company. It actually gets worse because not only do you lose that personal time, but you also have 100x the amount of stress.