In the powersport world I have several torque wrenches by my side when I'm working on them. I don't use cheap wrenches, Snap-on.
And one torque wrench will not cover all jobs.
I learnt very quickly that alot of the material used in powersport will damage very easily such as the casting's.
Overtightening is a very common mistake, even though you think you have the correct torque on a fasteners, it is unlikely and more likely over torqued. I have seen more stripped threaded holes and fractured bolts on motorcycles and powersport in general then any other motorized vehicle application. That is when I know if a butcher was last to work on it or not...LOL
Another tool sitting next to me is Loc-tite. Using the correct loc-tite will protect the fasteners from seizing and prevent them from loosening from vibration. A mistake many make with loc-tite is TOO MUCH, you only need a drop and also too much loc-tite will effect the torque yield.
No I do not memorize the torque values no need, that is what a service manual is for, electronic or paper. Every tech is requires to have the service info in our shop before even starting a job. Including checking for service updates.