I'm currently waiting on a dryer solenoid in the mail. It's a project that got slightly out of hand, over time but (as of yet) under budget, and I've learned a lot about what's going on inside my dryer which is the best reason to take on a project like this.
At the end of the project the greatest satisfaction comes from knowing how my home appliances function, and understanding them well enough to be sure they are operating safely and efficiently. That, and being able to tumble-dry clothes and towels.
I suspect this is why most people do it. I know saving momey is why I fix and build things.
The internal warmth from the glow of saving that money instead of hiring a plumber lasted at least 3 days.
Another part of the equation is - don't be afraid to ask for or hire help. Some people take on some projects because they don't want to or don't know they can ask for help.
the ikea effect in action...
I don't think it applies in this case however. There is no explicit cognitive bias at play. There would be if he considered his job is as good or better than plumber's (although actually, unless he has a very particular toilet setup, doing a good job after meticulous research and preparation is not out of reach at all).
In any case, even doing an OK job which is definitely worse than a plumber's but holds (and will presumably hold) is still a win if you're short on money but can spare the time/motivation.
Then again, I used to work in a retail position where I assembled so many things with far inferior construction and instructions. All in a day's work.
OTOH when people kitbash or modify Ikea furniture, I think that extends a bit into DIY. But putting it together out if the box doesn't count IMO.
I think some people just have a mental block when it comes to this type of activity. Imagining how two parts will fit together in the physical world or perceiving an order of operations to assembly, even if laid out in an easily parsed instruction booklet, just causes their brain to disengage for some reason.
With a job, "stop starting and start finishing" is an important mantra.
With DIY I think if you have too many projects, you give up on a project, or you just lose interest... It. is. OK!
Really, there's no reason to add to your many responsibilities at the cost of losing your enjoyment, your playfulnes, or your stress relief.
“But yield who will their separation,
My object in living is to unite
My avocation and my vocation
As my two eyes make one in sight.
Only where love and need are one,
And the work is play for mortal stakes,
Is the deed ever really done
For Heaven and the future's sakes.”
― Robert Frost
I've been a DIYer/maker/whatever-its-called-this-year since as long as I can remember. It doesn't mean I'm going to feel pressured to spend weeks fix the family TV rather than just go buy a new one on the day, and it doesn't mean I need to fix/build every single thing in the house. It just means I enjoy making/fixing/building projects when inspiration strikes.
I keep it as a hobby by picking and choosing which projects I'll actually enjoy and/or which ones will benefit me in some way ($20 DIY fix on a $900 washing machine "benefits" me even if it's not as enjoyable).