The ideas and progress of science are always exciting to me – I spend a lot of time reading about what other scientists do…
Having said that quite a lot of lab work is a repetitious and the problems that crop up (equipment breaking, running out of reagents etc) can be taxing. It is often necessary also to step back and say “OK, so I’ve done this thing 20 times and it didn’t work (and I am bored!) – is there a good scientific reason to carry on, or is it a waste of time?”
We have to be practical but keeping things interesting is important – that’s why I have usually got a few experiments on the go at any one time!
Like Richard said it can get a bit boring and repetitive at times. But really it can be more frustrating than boring. It takes quite a lot of mental strength to keep going and keep trying things when you can’t get an experiment to work or you can’t work out why it’s doing what it’s doing. A bit like it’s frustrating when you can’t work out an answer to a question in your homework.
Sometimes you just have to try something else for a bit and come back to it later with new ideas or ask someone else what they think. But it’s all worth it in the end when you get things to work because you’ve achieved it!