Of course! Here’s what you need to know:
Large publishers prefer agented submissions because the work arrives pre-vetted. They’re not wasting their time on an amateurish screed from someone who thinks they’re a writer because they own a copy of Word and know how to stuff a manila envelope full of their poorly-written, spell-check-ignored ‘manuscript’ and fire it off (unsolicited) to the President of the publishing company.
Agents exist, in part, to spare editors from sending more paper to the local recycling facility.
If you have bona fides—actual credentials—you can approach a publisher directly. But you follow their roadmap, not yours. No serious publisher accepts unsolicited manuscripts, but most will consider a query letter and book proposal (for non-fiction), or a synopsis and sample chapters (for fiction) — IF the writer conducts themselves professionally.
That last word there is doing a lot of heavy lifting in that sentence.
Public Service Announcement:
I get inspired the same way I learned to write—by doing it. When I was a kid, I just wrote because nothing was standing between me and a blank page of onion-skin typing paper loaded into a Smith Corona typewriter.
I used to be a writer, and the best thing about it was that there was no expectation; I wrote, and no one expected anything. It was private work—messy drafts, late-night notes, parcels of thought I could toss out or keep without explanation. That freedom is the engine of getting better: you try things that look stupid on the page, you fail fast, and you learn what’s worth rescuing. There’s a calm in knowing nobody’s billing you for your honest mistakes.