From very recent experience (today!).
Took a day off work because I fancied some 'film time', drove to the coast, walked a way and found the first photo opportunity. Out with the camera, on to the tripod, frame, focus then reach for the lightmeter - reading - BAT! No problem, brought a second body for colour. Nothing! battery dead in that too! Tried that thing where you scratch the battery ends on a stone out of desperation and got a little response. Sunny 16 it is then!
I wanted to do some infra-red too so as exposure's a bit of a hit and miss approach the lightmeter 'issue' wasn't so bad. So you know the routine, frame, focus, put the filter on and expose a couple of shots. Move on to the next spot, remove filter, frame, focus, put the filter back on and expose. It's a simple enough concept, so why do I keep forgetting to put the filter back on!!
And the advantage of film is that when I get round to developing the film and cutting into strips of 6 I'll have a picture at each end of the strip and four blanks in the middle to remind me how good I am!