Like many London theatregoers, I didn’t book my tickets early enough to see Derek Jacobi’s legendary King Lear at the Donmar. But I really wanted to see it, so I turned up one winter’s day at 2.30 p.m., hoping to get a return. As I took my place on the stone floor outside the theatre, one of the two elderly ladies in front of me smiled broadly, “Thank goodness you’ve turned up,” she said. “ We were beginning to feel a bit silly. We’ve been here since 12 o’clock”. The next person came half an hour later: a frail, elderly man with a walking stick. The lady after him had tried queuing before, only to be turned away. So she’d come back, this time a couple of hours earlier than before.

As an actor, you’re often grateful for a house half-full. But if you’re lucky enough to be in a sell-out production like King Lear then you need to remember that your audience – at least some of them – are prepared to make considerable sacrifices to see you.

This helps give you humility, doesn’t it? When you stand on the stage, you honour your audience. And you show that best, with your humility and gratitude at having the chance to do your stuff, by giving the audience your best shot, night after night after night. For you it may be just another performance. For some of us it’s a memory we will cherish for decades. I still remember seeing Derek Jacobi play Hamlet at the Old Vic, more than 30 years ago.

You are also one of the lucky minority that has an acting job at all. (Just to remind you, the latest stats from Equity suggest that on any one night more than two thirds of the 42,000 British actors are out of work.)

I’ve met some actors whose default is a distain for the audience, and they act with an almost visible sneer. They may get work up to a point, but it doesn’t make their audience adore them, and it probably doesn’t make them happy to act. Such performances lack humility and tip into arrogance.

I’ve also met actors whose default is fear of the audience, dreading their collective judgement. This is an illusion. Do you really think audience members sets out for the theatre and plonk themselves down in their seats thinking, “I’m really going to make sure I hate this”? Their starting point is that they want you to be great. So you’ve got all this good will on your side before you even step into the space. Your part of the deal is to give them a good night out.

Humility is based not on hate, but love. You put yourself through it all, not for therapy or ego boosting, but for the love of your audience. That doesn’t mean you can’t have dignity. Having humility allows you to be grounded. (Consider: the word comes from the Greek: humus, meaning ground.) You sometimes see this mixture of love, humility and dignity in veteran show biz performers. The Broadway singer Barbara Cooke has given many a heart-felt one-woman show that embraced her adoring audience with boundless humanity. And at the age of 78, Debbie Reynolds so loved her West End audience, and gave them everything she had with such heart that grown men ran down the aisle to plant kisses on her cheeks – kisses she graciously accepted. Such women are legends.

Going back to that evening at the Donmar, in the end, after waiting for five hours I was lucky. And as I settled into my seat, I glanced across the auditorium at the two elderly ladies, the man with the walking stick and the lady who had tried a second time. And when the lights when down, Derek Jacobi and his fellow actors gave performances of such energy and generosity, that we all sat on the edges of out seats, hardly daring to breathe. That was a night to remember.