There are so many times in a day when you say "How irritating" But whens that? Varied reasons from food to technology to people can disturb your mental balance.
When your internet connection is disrupted without your knowledge or your laptop doesn't start, When your cellphone battery goes dead on a busy day and you don't find a charger. Even if you do, your cell doesn't agree to charge.
With the rains the roads are so jam packed that the traffic can get on your nerves.
When someone wakes you up on a early morning even when you have no class or college.
When the auto rickshaw fellow charges a whooping sum instead of the normal fare.
When some friend constantly keeps bugging you.
When you are searching for something franticly and you don't find it till the end.
And of course when you are terribly terribly hungry ;)
Many more such simple n stupid reasons which irritate us. Let me know the instances when you say "Grrrr...Its irritating"