My general experience with DIY is that everything takes four times longer than you expect, almost by definition. There is always at least one unexpected problem ing which distracts from the original idea and has to be solved before progress is possible.
When I was putting up the lighting over the weekend I found that the cable box I'd used wasn't flush with the ceiling. So I had to spend an extra forty minutes or so cutting a hole for it first - and a fairly simple job turned into a less simple one.
This is why I'm not very romantic about DIY. In theory it's good for the soul, but mostly it feels time-wasting distraction to me. Even when the results are good - the lighting makes a huge difference to the studio/gallery - I don't much enjoy it, and I can easily think of other things I'd rather be doing.
So, yes, patience may be overrated and I do need to work on the followthrough, but for me patience (and probably 10 times more time than budgeted) is it. Can the last politician to go out the revolving door please turn the lights off?
I used to be annoyed by these realities as well. Now, I expect them. And of course, the world being as perverse as it is, once you become mentally prepared for the big distraction, it doesn't show up ;-)
I haven't done this sort of thing for maybe 25 years. Now that my S.O. knows about my skills, she dreams up new uses for them. Fortunately, projects seem to go a LOT smoother than I remember. "Remember the I35W bridge--who needs terrorists when there are Republicans"
I'd guess if you've been doing it for a while it gets to be more a case of 'This is probably going to happen, and then I'm going to solve it this other way.'
If it's all new, it's more of a challenge.
Also - tools. The professionals have the specialised tools, and they know which ones they need. If you're new to the game it's not obvious which tools are required, or even if they exist. (An obvious example being the tap spanner, which turns a horrendous under-the-sink job into something rather easier.)
