Yes, and I have to say I find this the hardest part of the Russian language (that and sentence structure); sometimes I just look at a familiar verb and draw a complete blank. 90% of the time I need a dictionary it's for this reason. Prefixes are fairly predictable, a lot of 'roots' of verbs are too, but add this to variable meanings with reflexive endings, and the number of verbs that sound or look very similar to each other, and verbs with a wide range of meanings, and I'm often completely stumped, even if it's a verb I've seen a few times before. Anyway, I'm not complaining...!