My first rehearsal of the next Narnia play yesterday. Felt quite uncomfortable (apart from not having been feeling the best health-wise most of the week); couldn't even get my first three lines out without reference to the script and nothing seemed to be moving along well. The three 'kids' (Edmund, Eustace and Lucy) were going so well (having had an extra rehearsal earlier in the week) that they were doing their first scenes without scripts at all. Bit off-putting!
Still, I think whenever people start rehearsing a play there's a time when you think, 'Anything I do will look silly,' and, 'Everyone else has got it together, how come I haven't?' Neither of these things is true, and furthermore, the other actors will be feeling just as uncomfortable in those first rehearsals as you do. You need time to get used to each other, to get settled into how you're going to play the particular role (and this can go on for several weeks, when the rehearsals are spread out over three months, as ours are), to feel as though you're getting the hang of what the director might or might not want (even when you've worked with him/her before), and in general you need time to get over plain ordinary nerves; not the sort of nerves that render you paralytic, but the sort of nerves that everyone has in starting something new - and each play you do is something altogether new, however established an actor you are.
Acting requires a period when you have to just let go and forget about what the other actors think - in fact, they'll be doing exactly the same, wondering what those around them think of their work. We're all pretty sensitive, really, us performers!