Recently I realised that I've been using two bridge-related idioms quite often. Being two completely unrelated idioms, one can associate them with attitudes towards life.
1. Water under the bridge - something that happened in the past cannot be changed and hence it is no longer important.
I believe that something that cannot be undone does not require our attention and brooding over that event only causes us distress.
2. Cross that bridge when one comes to it- to not worry too much about potential problems that may occur in the future.
Yes, it is wise to plan for the future and prepare for it but one should not hone a pessimistic attitude towards it. If a certain problem does arise in the future, deal with it then. Ruining your current state of mind is never worth it. We'll-cross-the-bridge-when-we-come-to-it attitude can also help one live in the present and not stress too much about the future.
These two idioms have definitely helped me simplify my thought processes, and I thought I would share them with you!