I grew up with the IRA bombing campaigns; after university, I went to Israel to work until my early 30s (I am not Jewish) - during the 90s, we were subjected to bus bombings and suicide bombings. My bus to work was targeted two Sundays running (that felt a bit personal) as well as my bus to University. Our University refectory was targeted. Teenagers were killed whilst queuing up to go into a nightclub. Markets, coffee shops, shopping malls and bars were bombed. I didn't stop going out, studying, going to work, shopping or anything else - because that is how terrorists win.
You adapt a little - of course you do: you keep an eye open for bags left alone, and ask about them (I still do this in the UK, and have done since I returned - just like we used to in the bad old IRA days) - for a while, I was hyper-alert if I ever needed to queue outside for anything. It has taken me literally years to be able to sit in the window of a coffee shop or restaurant (you don't sit by the window to avoid being shredded by the glass if there's a bomb outside) in the UK. But you don't stop or change what you are doing, because you will not let them win. Yes, of course, sometimes you are frightened (in Israel in the 90s, they would sometimes release when there was a suicide bomb suspect on the lose, to encourage the public to be hyper vigilant at the time) and sometimes, you stay home (when there are announcements on the radio that everyone near the MFA asks the public to stay in because there's a gunman on the loose): but that's not the same as allowing disproportionate fear to interfere with your plans.
What happened yesterday was a tragedy: but if you let it dictate your movements, then the terrorists have won another small victory.
(For reference: fireworks sound nothing like a bomb, and not very much like gunfire)