fret and write posts titled "Is my beer ok?" on HBT.
To add to conversation: I used to fret alot about mash temps and what was going on in my mash tun. I ended up doing more harm than good in my POS mash tun by mucking with the mash too much (taking off lid, taking temps, stirring, etc.). I also would mash in way hotter than I needed too (because its easier to cool off than to heat up!) which caused starch conversation to occur more quickly and I was actually getting overattenuated beers.
Now I have a process where I hit my mash temp semi-accurately (no more trying to hit a temp within 1 degree...I basically mash at High/Medium/Low), I don't check my temps during the mash, and I start my sparge 30-45 minutes of mash (today's brewing grains seem to convert within minutes of mashing in).
Here is where having good, predictable equipment trumps constant monitoring of conditions. At least when it comes to having an enjoyable brew-day.