Rob Lowe got sober after he had to go to sleep instead of answering his mother’s call about his grandfather suffering a heart attack. The 60-year-old ‘St Elmo’s Fire’ actor hasn’t had a drink in 34 years, and has now said his decision to give up booze wasn’t the result of a sudden revelation – but instead a process of self-reflection marked by a string of wake-up calls that led up to the shocking moment he missed his mum’s desperate calls about his grandad’s health crisis. He told People: “Getting sober was an incremental decision. It’s baby steps until you’re ready. You can’t do it until you’…