Here in London we have had a lot of shocks over the last few weeks and we don't know if it is over. The extra police presence is comforting, but it is also a daily reminder of the risks we face.
Many of us are trying to return to normal, but how can we start to concentrate on work and living again?
First, accept that the real risk is still tiny compared to being run over crossing the road, riding a bike or even doing some DIY. Figures published by Transport for London show that 216 people lost their lives in 2004 on London's roads.
Next choose where you put your attention. A road sweeper looks behind him at the clean street when he wants to feel good. Likewise, we can also decide where to look and where not to.
Try watching and listening to less news. The media does not help with shifting perspective. Limit your news consumption to once a day - or even less - and then catch up once a week. Don't start or end the day with news. Choose something more uplifting instead.
Be grateful. Write down three things you are grateful for each day. They can be big or small – you might be grateful that your relationship with a family member is going well or that your iPod is going well.
Your health, your friends, the he choices open to you, access to clean water, music, the weather, even just being alive, all these have an impact on how you feel.
Maintain this for 30 days and your life will feel different.
At the end of each day write down three things that you achieved that day. Usually we move so quickly from one task to another that we don't give ourselves any credit for what we have achieved. So take a few moments and acknowledge some positives. Often these amount to more than we thought.
Even better, agree with a friend remind each other to do this at the end of the day.
Your energy levels also impact those around you. If you are managing others you have to look upbeat or you drag others down, affecting their productivity. Your mood is a matter of scrutiny for those you manage. Ask yourself after every interaction, did you just help somebody to achieve more or less by the way you came across?
Remember to do things that make you feel good. This might be running, woodwork, painting, singing, dancing, playing an instrument, volunteering etc. Pick two things that you know give you energy and then set aside 15 minutes to plan how you are going to make them a bigger part of your life. All you have to do is take one step forward. Treat this as a wake up call to enjoy life more today.
Take another look at your goals for the year, if you have them, and make sure you are making progress.
Finally, try to connect with people more. As humans we hate isolation. Get in touch with friends and family and spend more time with them. If you are busy, make a few three-minute phone calls to people who make you feel special.
And take the opportunity to talk more with people in queues or on the train. Because it is little things that will help to make the world feel like a more friendly place for all of us.