I poured myself a cup of coffee in the teacher's lounge and took a sip. It wasn't Starbucks, but the jolt of hot, steamy caffeine helped wake me up.

Reference to:

Possible meaning:

The possible meaning of this statement is that the person needed to consume coffee to help them feel more awake and alert. The mention of it not being Starbucks suggests that the coffee may not have been of premium quality or from a fancy coffee shop, but it still served its purpose in providing the energy boost the person needed.