Floyd Mayweather has one helluva watch collection -- 41 time pieces in total -- including a crown jewel, the $18 million "One and Only." Seems Floyd was just bored on Wednesday and felt like stuntin' on all of us normies -- so he broke out the briefcases with his super expensive man jewelry ... and showed it all off. "When I go on pay-cation for 30 days," Floyd said ... "I take 30 watches with me." "But, you know what, if we add 10 more days, I take 10 more watches," he explained while opening a 2nd case. And, then the big daddy ... "But then, I say 'f*ck it. If I wanna bring out the one and only, then I'll take ... (full story)