UNDERSTAND

ZZBUALDRINAstronaut for whom a Pixar character is named MEMORYLANETake a nostalgic trip down this (6,4) STRIPPOKERCard game that's really taking off? BIGBROTHERUbiquitous leader is great alongside fellow union member (3,7) SUPERWOMANShe flies American back every week to country (10) METHUSELAHBiblical patriarch – bottle holding six litres of wine (10) THATDOESIT"Enough already!" ZZZZFUYWUYBear of children's rhyme MAGNACARTADocument sealed at Runnymede in 1215 (5,5) HIGHSTAKESWith a lot on the line, or a phonetic hint to 3-, 8-, 15-, and 23-Down AUTHORSHIPWriting this, hour wasted filling a puzzle at the beginning (10) CEREBRATEDThought before entering bet, card getting dealt (10) MINDTHEGAPWarning on exiting tube train (4,3,3) SETTOMUSICNoted work?