Can you catch the same viral infection twice in one season?

Yes, and it happens more than people expect. There are hundreds of distinct viruses producing similar cold symptoms, so back-to-back illnesses are usually two different infections rather than one relapsing. Even within a single virus, immunity after infection can be short-lived and partial — this is well documented for COVID and for influenza across seasons. Reinfection also tends to look milder. If you are getting genuinely frequent infections with slow recovery, that is worth investigating rather than accepting, particularly if you have diabetes or are on immune-suppressing medication.