I have been in Los Angeles for the past few months in an attempt to see if I can make a career out here. There is nothing interesting to discuss about this vanity project except for the fact that it has made me think I might be prejudiced about racism.

Before I first arrived in the US, I had been bombarded with advice from my friends about the nightmarish experiences that anyone brown faces at immigration, and warned that I should steel myself for a thorough interrogation and a cavity search. This turned out not to be the case, as I was welcomed by the officer at immigration and wished well on my new journey. He then started discussing astrology with me, which I couldn’t give a shiny shit about, but obviously had to feign interest to avoid immediate deportation.

I had also been reliably informed, and indeed had formed the impression myself, that LA represented the most liberal corner of North America and if I was going to be welcomed anywhere it would be there. I was involved in a racial incident within the first 24 hours of my arrival.

I was walking into a bar with a friend when a man immediately clocked me and followed me in. He looked drunk, but determined to meet my gaze, which I avoided through a combination of survival instinct and lazy eye. As I made my way to the bar, he planned a route to take him directly in front of me and gave me a solid shoulder check.

“Where are you from?” he barked at me. “London,” I replied, which is what anyone from Crawley says when abroad. “No, you know what I mean. Where are you actually from?” I started to wonder if he did actually know I was from Crawley, but then realised that what he was really asking was: “Why are you brown?”

I told him my family are Sri Lankan. He asked me if I was Muslim. I told him I wasn’t. He then asked to buy me a beer. I couldn’t figure out whether this was to congratulate me for not being Muslim or if he was performing the well-known “see if it’s Muslim by offering it alcohol” test. I refused. He insisted. I refused. He aggressively insisted. I accepted. It was at this point that my friend walked over from his seat. There is another column to be written on how long it took that dickhead to intervene, but we are discussing different issues here. The man went on to apologise and explain he had barged me because he thought I was Muslim, that I should know Islam is evil and that he would like to discuss with me why that was.

My friend and I lied and said we hadn’t seen each other in years and wanted to catch up, at which point he left us to it. Which is fine, except for the fact I had not engaged with and tried to change the views of a man who was prejudiced. I had decided that a drink with a mate was important enough to allow an idiot to continue believing these mad things and telling them to other idiots who might believe him.

On the other hand, why the hell should I? I am not obliged to tackle racism wherever and whenever it occurs, nor am I qualified to do so. I spent the next few days hoping he would go to prison and be on laundry duty with a really nice Muslim guy who would change his mind about Islam. (But then I had just rewatched American History X so that might have been optimistic.)

It was only a couple of weeks later that my attitudes towards racism were once again brought under scrutiny. My family and I were at a restaurant having dinner with an all-white family (I mention this because it’s relevant to the story, not just because I want to show off that I have white friends) when an older woman approached our table.

“I have been watching you all evening, and I have to say how wonderful I think you are.” Nobody at the table had any idea what she was talking about, but, I have to admit, a small part of me hoped I might have been recognised so that I could demonstrate to my wife that I did in fact have some profile over here and this move to the US wasn’t a complete waste of time. My dreams were immediately shattered, however, when she announced to most of the restaurant: “This is what America is all about. Families eating together regardless of colour! This makes me so happy. And I’m saying this as a Republican!”

I sat in astonishment as my wife and friend discussed how nice that was and what a positive experience we had just had. I firmly disagreed. I made the point that we were just sitting having dinner and that we should be able to do that without it being commented on or misinterpreted as some sort of social statement. My wife and friend, however, felt that this woman might have felt like she had made some progress in her attitudes and that her approaching us to share that was something to be celebrated.

On both of these occasions, I felt that my response to what was happening was insufficient and that perhaps I have a responsibility to tackle these beliefs to help combat discrimination. But, mostly, I just want to have a quiet Mexican meal with my token white mate.

• Romesh Ranganathan is an actor and comedian