You're absolutely right! I hadn't thought to blame casting (ah, someone else to blame!), but there really is astounding similarity among the cast members. Sometimes I even have trouble telling Young and Scott apart from a distance. I never had this trouble on SG-1 (not even when Ben Browder joined the cast!) or SGA (perhaps while the three you confused do look similar, their voices are quite distinct, and at least two of them were always talking!). TJ was one of the first people I could identify. I needed other people's help to connect Lt. James later in the show with the woman we saw with Scott in that very early scene in the premiere—and, dang it, to realize that was Scott, and not some other white kid. I can tell Eli apart, too, and Rush.

I never got into Lost; I think the biggest reason is that I hate seeing characters killed. I missed the beginning of it, and by the time people were telling me "You have to see this!", I already knew major characters were dying. Maybe someday I'll watch—but I've seen enough ads to know what you mean about different looks, ages, and body types.