There was something on the radio that stopped me in my tracks… a young woman, in her 20s with a serious, long-term health condition was saying that, standing on trains, she experiences a lot of pain.

But hardly anyone offers her a seat. She looks young, fit… so why would they? She's afraid to ask in case, as sometimes happens, the person with the seat doesn't believe her. It's embarrassing to explain.

I'm 66 but lucky enough to have no problem standing. Yet it's never occurred to me to offer my seat to someone younger unless they're obviously disabled, struggling with children or similar.

I guess we all need to use our imaginations.

That thing about imagination was brought home to me recently when I did some Dementia Friends training with Age UK Norwich, where I volunteer.

Did you know people living with dementia can sometimes 'see' a darkly-coloured mat as a hole or area of water?

MORE: Group has vision to make Norwich a dementia-friendly city as 35pc growth in prevalence beckonsWithout that fact, if you spot someone standing at the edge of a large mat, looking confused, you'd be baffled. Knowing it, you just might walk across, say: 'That's just a mat. Would you like to take my arm? We'll walk across together.'

It's meeting that invisible need, once again… and just takes a bit of know-how.

The Dementia Friends movement has been spreading this message for several years. Google it. The basic training takes just an hour or so – and can put you in a position to understand and change someone's day.

MORE: Pledges to make Norwich 'dementia friendly' pour in from across the communityMy city-based charity is a leading player in the Dementia Action Alliance challenge to make Norwich a dementia-friendly city by 2018, with the aim of training 7,000 dementia friends.

This newspaper is a strong supporter and Age UK Norwich's Marie Lucas will offer free training for your workplace or club. (Call her on 01603 496333.)

More than 30 organisations have already pledged support. Out in the county, our sister-charity Age UK Norfolk is doing wonderful work to create dementia-friendly towns. Above all – as I started by saying – it's about being alert, thinking about hidden needs.

On Thursday May 18 at 1pm at The Forum in Norwich, we will celebrating all those who have already become Dementia Friends by urging them to join us, and meet each other. See you there.