David Weston.

In 2010, David Weston was a teacher at Watford Grammar School for Boys in Hertfordshire, England.

During an assembly that year, Weston stood up in front of all 1200 boys at the school and told them he was a gay man.

And, four years later, he received a letter from a former student which made him realise just what a big deal it was.

He tweeted:

The letter has been retweeted over 4000 times.

David spoke to the Daily Mail about his decision to come out in front of the school community:

It just goes to show that we all have the power to affect the lives of those around us, even if we don’t understand it at the time.

Have you ever waited a long time to say ‘thank you’ to someone?