It sounds like this workplace has glaring issues with onboarding/mentoring and documentation/knowledge transfer. Maybe deeper issues, too, as it seems you're a

It sounds like this workplace has glaring issues with onboarding/mentoring and documentation/knowledge transfer. Maybe deeper issues, too, as it seems you're a bit afraid to ask "stupid" questions? Remember, everyone has blind spots. Seniors especially can have blatant and surprising ones. Where I'm at we know our documentation is bad and our systems complex, so diligently treating every question, whether from a junior or senior, with respect and answering in a manner that teaches and inspires confidence is seen as a duty. A "simple" question will often prompt workshop-like answers with whiteboarding, etc. When you walk away from that conversation you should feel good about having dared to ask what you might have thought was a "stupid" question. The next time you ponder whether to ask for help or not you should hopefully feel less hesitant. Anyone brushing off or not taking a junior's questions seriously should keep in mind that they too have blind spots.