During a PhD it's important to take time to think and to consider different options.But too much thinking can also be a bad thing.If you always second-guess yourself - or if you always chase the new ideas - then you may never commit to anything.Sometimes it's better to stop thinking and just take action.You might make mistakes. Perhaps big ones. This is OK.It's by making mistakes that you have the opportunity to learn.The biggest mistake is not to try.So stop worrying and just do it.